Easy DIY Galaxy Cake: A Cosmic Buttercream Recipe for Stellar Celebrations

Embark on a delightful culinary journey into the cosmos with this quick and easy DIY galaxy cake! Bursting with vibrant colors and a shower of sprinkles, this galaxy birthday cake is not only incredibly fun to make but also visually stunning, making it the perfect centerpiece for any kids’ space-themed party. Get ready to create a truly out-of-this-world dessert that’s far simpler than it looks.

*Thank you Pillsbury™ for sponsoring today’s post. As always, all opinions and text are mine.*

With Space Exploration Day approaching on July 20, I was inspired to celebrate like an astronaut, and what better way than with this breathtaking cake? Its cosmic beauty is on par with my popular Galaxy Cupcakes (With Buttercream Icing) and Galaxy Cookies (Buttercream Icing). You might have seen intricate mirror glaze or fondant galaxy cakes trending, which often involve many complex steps. However, this recipe takes a different, much more approachable route. Instead of demanding advanced techniques, we’ll achieve this celestial masterpiece using simple frosting or buttercream icing, making it significantly faster, easier, and less intimidating for bakers of all skill levels.

This beginner-friendly version is ideal for children’s birthday celebrations, especially those with a captivating space theme. Even if you’ve never frosted a cake before, you absolutely can create this! Take a closer look at the stunning galaxy frosting, and you’ll discover captivating swirls of rich purple, deep blue, and pristine white. This mesmerizing color effect is achieved by artfully blending white, aqua blue, and purple frostings, reminiscent of the ethereal beauty of the Northern Lights. And here’s a little secret: the inside of this cake is just as delightful as its exterior! We’re using a Funfetti cake base, which means every slice reveals a playful explosion of colorful candy bits, ensuring a soft, moist texture with the perfect amount of sweetness and fun.

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Why You’ll Love This Easy Galaxy Cake Recipe

There are countless reasons why this DIY galaxy cake will become your go-to recipe for any cosmic celebration. Forget the stress often associated with elaborate cake decorating. This recipe champions simplicity without compromising on impact or flavor. Here’s why it stands out:

• Effortlessly Stunning: Achieve a professional-looking galaxy effect with minimal effort and no special tools required beyond basic baking equipment.
• Kid-Friendly Fun: The process is simple enough for little hands to help, making it a fantastic family activity and creating wonderful memories. Plus, kids absolutely adore the vibrant colors and sprinkles!
• No Fondant, No Mirror Glaze: Unlike many trending galaxy cakes, this recipe uses easy-to-work-with buttercream, eliminating the need for complex fondant sculpting or tricky mirror glaze application. This means less stress and more fun!
• Delicious Funfetti Base: The Funfetti cake on the inside adds an extra layer of joy with its colorful candy bits, complementing the cosmic theme perfectly. It’s moist, tender, and always a crowd-pleaser.
• Customizable: Easily adapt the colors and sprinkle choices to match any party theme or personal preference.
• Perfect for Any Occasion: While ideal for space-themed birthdays, this cake is also wonderful for school events, movie nights, or just a fun weekend baking project.

Key Ingredients for Your Cosmic Cake

Crafting this stunning galaxy cake requires just a few essential components, many of which you likely already have in your pantry or can easily find at any grocery store. The beauty of this recipe lies in its simplicity and accessibility, allowing you to focus on the fun of decoration.

• Cake– For an extra pop of color and celebratory feel inside, Funfetti cake is absolutely the best choice for this space-themed creation. Its built-in sprinkles add a delightful surprise to every slice. You can use a boxed mix for convenience, or your favorite homemade Funfetti recipe.
• Frosting– The magic of the galaxy effect truly comes alive with the right frosting. You’ll need three key colors: white, aqua blue, and purple. You can opt for homemade buttercream for a richer flavor, or save time with high-quality store-bought frosting. If using white frosting, you can always divide it and use gel food coloring to achieve the aqua blue and purple shades.
• Sprinkles– To truly mimic the glittering stars and celestial dust of a galaxy, a pre-made space-themed blend of sprinkles is highly recommended. Look for mixes that include stars, edible glitter, and varying shades of blue, purple, and silver for the most authentic cosmic effect.

How to Make Easy DIY Galaxy Cake with Buttercream Icing or Frosting?

Creating your very own galaxy cake is a surprisingly straightforward process that yields impressive results. Follow these simple steps to bring the wonders of the universe to your dessert table.

1. **Bake Your Cakes:** Start by preparing your cakes according to the package directions (or your chosen recipe). For a multi-layered effect, I typically make three cake layers, which adds to the grandeur of the final product.
2. **Cool and Level:** Once your cakes are baked, allow them to cool completely on a wire rack. This is crucial for preventing your frosting from melting and sliding. If your cakes have domed tops, use a sharp serrated knife to carefully level them, creating flat surfaces for stable stacking.
3. **Stack and Crumb Coat:** Place your first cake layer on your chosen cake stand or serving plate. Spread a generous layer of white icing evenly over the top. Carefully place the second cake layer on top, gently pressing down. Repeat with another layer of white frosting and the third cake layer. Then, apply a thin layer of white frosting all over the entire cake – this is your “crumb coat,” which traps any loose crumbs and creates a smooth base. Chill for 15-20 minutes for best results.
4. **The White Canvas:** Once your crumb coat is firm, apply a thicker, even layer of white frosting over the entire cake, smoothing it as much as possible. This white base will serve as the canvas for your galaxy swirls.
5. **Add the Colors:** Now for the fun part! Randomly dollop spoonfuls of purple and blue frosting all over the white-frosted cake. Don’t worry about being precise; the more random, the more natural the galaxy effect will appear.
6. **Swirl the Galaxy:** Using a clean offset spatula or a bench scraper, gently and lightly blend the colored frostings into the white. Make broad, sweeping motions, rotating your cake as you go. The key is not to overmix; you want to see distinct swirls of purple, blue, and white, creating that beautiful nebulous effect, rather than just one solid color.
7. **Sprinkle Stardust:** Generously decorate the top and sides of the cake with your galaxy-themed sprinkles. Press them gently into the frosting on the sides to ensure they adhere well. These sprinkles will represent the distant stars and glitter of the cosmos.
8. **Pipe Stars and Ruffles:** Finally, for those finishing touches that truly elevate the cake, use a piping bag fitted with a star tip (or a pre-filled pastry bag) to pipe small stars in a circular formation around the top edge of the cake. Then, pipe ruffles or a decorative border along the base of the cake to give it a polished look. And there you have it – your very own edible galaxy!

Two Main Components of a Milky Way Cake

Achieving that stunning, recognizable galaxy effect hinges on perfecting two key elements: the vibrant frosting and the dazzling sprinkles. When executed thoughtfully, these components transform a simple cake into a cosmic spectacle.

1. Frosting: The heart of your galaxy cake lies in its colorful frosting. The hues need to be exceptionally vibrant to truly capture the essence of deep space. You have a few options here:
   • DIY Colors: Start with plain white buttercream and use high-quality gel food coloring to create your desired shades of purple and aqua blue. Gel colors are concentrated, producing intense, rich tones without thinning your frosting.
   • Pre-Colored Icing: For ultimate convenience, purchase pre-colored aqua blue and purple frostings. This saves time and ensures consistent color saturation.
   • Technique is Key: Remember, the swirling technique is more important than perfect application. The blending of the colors is what creates the dynamic, nebula-like appearance. Don’t be afraid to experiment with your spatula movements!
2. Sprinkles: Just as the real galaxy is composed of countless stars, planets, and nebulae, your cake needs a diverse array of sprinkles to convey that celestial depth. Don’t just stick to one type!
   • Variety is the Spice of Space: Use a combination of sprinkles with different textures, shapes, and sizes. Think tiny nonpareils for fine stardust, larger star-shaped sprinkles for prominent stars, and perhaps some edible glitter for a shimmering, ethereal effect.
   • Color Harmony: Focus on blue and purple hues, along with silver and white, to complement your frosting colors. This creates a cohesive and visually rich galaxy scene.
   • Strategic Placement: While you’ll scatter many, consider placing some larger, more distinctive sprinkles strategically to represent planets or prominent star clusters, adding depth and interest to your cosmic landscape.

Do you notice that perfectly piped frosting around the top and base of the cake? While I traditionally achieve this by filling a piping bag with icing and attaching a star tip, this time I leveraged an incredibly convenient product: Pillsbury Filled Pastry Bags. These innovative bags come pre-filled with frosting and have an attached star tip, making the piping process incredibly fast and hassle-free. The best part? Since the bags are disposable, clean-up is minimal, which is always a huge bonus! Currently, they’re available in three delicious flavors: Vanilla, Chocolate Fudge, and Cream Cheese, offering versatility for various baking projects.

Tips and Techniques for a Perfect Galaxy Cake

Even though this galaxy cake recipe is designed to be simple, a few expert tips can elevate your creation from good to absolutely stellar. Pay attention to these techniques for the best possible results and a smooth, enjoyable decorating experience.

• Chill for Piping Perfection: For the cleanest and most defined piping results, especially when using pre-filled pastry bags or homemade buttercream, chill your pastry bag in the fridge for at least 20 minutes before you start piping. This helps the frosting firm up slightly, preventing it from becoming too soft and smudgy under pressure.
• Patience with Cooling: Always, always ensure your cake layers have cooled down completely – and I mean *completely* – before you even think about applying frosting. Warm cakes will melt your frosting, leading to a runny, messy disaster and compromising the structure of your layers.
• Master the Swirl: When using a spatula to spread and blend the colored frosting around the cake, exercise caution and a light hand. The goal is to create beautiful, distinct swirls of purple, blue, and white, mimicking nebulae. If you overwork the frosting, the colors will blend too much, resulting in a muddy, uniform purple or blue cake rather than the intended vibrant galaxy effect. Think of it as painting with a very soft touch.
• Galaxy-Themed Sprinkles are Key: While any sprinkles will add sparkle, investing in actual galaxy-themed sprinkles will dramatically enhance the overall cosmic look. These often include tiny stars, moons, and a mix of iridescent and metallic finishes that truly capture the celestial magic.
• DIY Solar System Additions: For an even more immersive solar system cake, get creative with planets! You can easily cut out pictures of planets from thick cardstock or print them out, then attach a toothpick to the back of each. Gently push these into the top of your cake to create a three-dimensional display of our solar system.
• Pillsbury Power: I personally used Pillsbury products for this cake, specifically their Funfetti® Cake Mix and Pillsbury Filled Pastry Bag, which made the entire process incredibly hassle-free and enjoyable. The wonderful team at Pillsbury also sent an amazing package of space-themed goodies, including galaxy sprinkles, a viewfinder, NASA oven mitts, and a solar system map. My son absolutely adored the viewfinder and the cute gloves, proving that baking can be an experience for everyone!

Speaking of kids, this is truly one of those easy cake decorating projects where even the youngest members of the family can lend a helping hand. It’s a fantastic way to create lasting memories and bond over a shared creative activity. My little one was an incredibly cute and enthusiastic assistant, thoroughly enjoying the process of bringing our cosmic creation to life. He had so much fun adding the shimmering sprinkles to the cake, turning it into a dazzling starfield, and even bravely tried his hand at a little piping – adorable attempts, indeed! But without a doubt, his favorite part was the playful interaction with the colorful sprinkles and, of course, sneaking spoonfuls of the delicious frosting whenever he thought I wasn’t looking. These are the moments that make baking so much more than just making a dessert; they’re about shared laughter and sweet experiences.

Storage and Make-Ahead Tips for Your Galaxy Cake

Planning ahead for your galaxy cake can save you a lot of time and stress, especially if you’re preparing for a party. Proper storage also ensures your cosmic creation remains fresh and delicious. Here’s how to best manage your cake before and after serving:

• Room Temperature– A frosted cake can generally be left out safely at a cool room temperature for approximately 3-5 hours. If your environment is particularly warm or humid, it’s best to err on the side of caution and refrigerate sooner.
• Refrigerate– To extend the freshness of any leftovers, store the cake in a sealed, airtight container. This will keep it moist and delicious in the refrigerator for up to 3 days. Make sure the container is large enough not to smudge the beautiful frosting design.
• Freeze– For longer storage, both the undecorated cake layers and the frosting can be frozen separately. Wrap cake layers tightly in plastic wrap and then aluminum foil. Store frosting in an airtight container. Both can last for up to 1 month in the freezer. When you’re ready to enjoy this cake, simply thaw the components to room temperature and then assemble and decorate according to the instructions provided in the recipe card below.
• Make Ahead– This galaxy cake is an excellent candidate for making a day or two in advance. Once fully assembled and decorated, store the entire cake in a covered box or a large airtight cake carrier in the refrigerator. This allows the flavors to meld beautifully and gives you one less thing to worry about on party day. Just remember to bring it out to room temperature about 30-60 minutes before serving for optimal flavor and texture.

More Easy Cake Decorating Tutorials You’ll Love

If you enjoyed decorating this galaxy cake and are looking for more fun and easy ways to elevate your baking, explore these other fantastic cake decorating tutorials. From whimsical designs to elegant finishes, there’s something here for every aspiring baker:

• How to Make Easy Fondant Bows
• Easy Beach Cake
• How to Make Ombre Cake (Blue)
• How to Make Naked Cake
• Easy Tie Dye Cake (Shirt Cake)
• Chocolate Pretzel cake
• Chocolate Bark Cake
• Peacock cake (And Cupcakes)

Recipe Card: Easy Galaxy Cake