Easy Galaxy Cake {Buttercream Icing}

Quick and easy DIY galaxy cake with lots of sprinkles. This galaxy birthday cake is fun, colorful and perfect for kids’ space themed parties.

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

With Space Exploration Day coming up soon on July 20, I wanted to get into the spirit and celebrate like an astronaut with this gorgeous cake. This is just as breathtaking as my Galaxy Cupcakes (With Buttercream Icing).

Now, this is not a galaxy mirror cake recipe nor is it a galaxy cake with fondant, which you have probably been seeing everywhere.

Both of those cakes require so many steps.

Instead of using fondant or galaxy mirror glaze, I made this galaxy cake with regular frosting and the new Pillsbury Filled Pastry Bag.

It’s faster and easier and not as intimidating either. This SIMPLE version is great for kids’ birthday parties, especially space themed parties.

Even if you have never frosted a cake in your life, you can make this cake!

Easy Galaxy Cake

Anyways, look closely at this galaxy cake frosting and you will see swirls of purple, blue and white.

I used a combination of white, aqua blue and purple frostings to create this cool color effect.

It reminds me of the beautiful Northern lights. Don’t you agree?

Quick and Easy Galaxy Cake Tutorial

The inside of this cake is just as pretty as the outside.

It’s a Funfetti® cake and just so much fun to slice into.

This cake is soft and moist and has the perfect amount of candy bits.

Galaxy Cake Recipe

In my opinion, the TWO main components of a really good galaxy cake are:

  1. Frosting: The colors need to be vibrant and blend together nicely – check out the colorful Funfetti® frosting options from Pillsbury, which are perfect for this.
  2. Sprinkles: You need to use a combination of sprinkles with different textures, shapes, sizes and lots of blue and purple hues. They should be similar to the real galaxy, which is composed of different things like planets, comets, stars.
Galaxy Birthday Cake

Do you see that piped frosting around the top of the cake?

Now, I used to typically do that by filling a piping bag with icing and attaching a star tip.

However, this time…I used a new product: Pillsbury Filled Pastry Bags.

The frosting comes in a bag with an attached star tip.

They are so fast and easy to use.

Since the bags are disposable, there is also very little clean up …Yay!

Currently, they are available in three flavors: Vanilla, Chocolate Fudge and Cream Cheese.

DIY Galaxy Cake

Here are some TIPS for making an easy galaxy cake:

  • For best piping results, CHILL the pastry bag in the fridge for at least 20 minutes.
  • Make sure the cakes COOL down completely before you start frosting them.
  • When using a spatula to spread the colored frosting around the cake, be careful not to go overboard or else you will end up with a purple cake instead of a cake with colorful swirls.
  • Use galaxy themed sprinkles for the best overall look.
  • You can also make a solar system cake with planets. Just cut out pictures of planets on thick paper. Attach a toothpick behind them and push them on top of the cake.
  • I used Pillsbury products to make this cake (Funfetti® Cake Mix, Pillsbury Filled Pastry Bag), which made the entire process absolutely hassle-free! The wonderful people at Pillsbury also sent me an awesome package of space themed goodies (galaxy sprinkles, viewfinder, NASA oven mitts, solar system map). My son LOVED the viewfinder and those adorable gloves!
Pillsbury Campaign

Speaking of kids, this is one of those easy cakes, where even kids can help out.

It’s such a great way to make memories with your family.

My kiddo was a very cute little helper and had so much fun assisting me.

He added sprinkles to the cake and even tried a little piping…hehe.

His favorite part was playing with the sprinkles and eating frosting by the spoonful …lol.

How to make galaxy cake?

The process is very SIMPLE. Start off by baking the cakes. Once they cool down, stack them on top of each other with icing. Then, frost the entire cake with white icing. Spread purple and blue frosting randomly all over the cake. Use a spatula to blend it all together. Decorate the top and sides with sprinkles. Finally, pipe stars on top of the cake and ruffles along the base of the cake. Enjoy!

Simple DIY Galaxy Cake
Print Recipe Pin Recipe
4.86 from 7 ratings
Rate this Recipe »

Easy Galaxy Cake

Prep Time: 10 minutes
Cook Time: 40 minutes
Decorating time: 20 minutes
Total Time: 1 hour 10 minutes
Quick and easy DIY galaxy cake with lots of sprinkles. This galaxy birthday cake is fun, colorful and perfect for kids’ space themed parties.
Yield: 10 People


  • 1 box Pillsbury Funfetti® Cake Mix
  • 2 cans Pillsbury white frosting
  • 1 can Pillsbury aqua blue frosting
  • 1 can Pillsbury purple frosting
  • 3/4 cup Sprinkles, Galaxy themed
  • 1 box Pillsbury Filled Pastry Bag


  • Prepare the cake, as per box instructions (I made 3 cakes).
  • Allow the cakes to cool down. 
  • Use a sharp knife to cut domes on top of the cake (if any). 
  • Place one cake on a cake stand and frost the top with white icing.
  • Place another cake on top of the icing.  Gently press it down and spread white frosting again. 
  • Place the third cake on top of the icing. Gently press it down and spread white frosting again.
  • Frost the entire cake in white icing. 
  • Use a spatula to spread purple and blue frosting randomly all over the cake. 
  • Use a clean spatula to spread frosting smoothly all over the cake until you have a swirled pattern of beautiful colors. 
  • Toss some sprinkles around the sides of the cake. 
  • Use piping bag to pipe stars around the top of the cake in a circle formation. 
  • Toss some sprinkles in the center of the cake. 
  • Use piping bag to pipe ruffles around the base of the cake. Enjoy!


  • Read all my tips above.
  • Leftovers can be stored in a sealed container in the fridge for up to 3 days. 



Calories: 242kcal, Carbohydrates: 54g, Protein: 1g, Fat: 2g, Saturated Fat: 1g, Sodium: 377mg, Potassium: 24mg, Sugar: 33g, Calcium: 109mg, Iron: 1.1mg
Course: Dessert
Cuisine: American
Calories: 242
Author: Abeer Rizvi

Well, that’s all for today.

If you liked this galaxy birthday cake, you should check out some of these other cake decorating tutorials:

How to make easy fondant bows

Easy Beach Cake

Ombre blue flower cake

How to make a naked cake

How to make a tie dye shirt cake

Pretzel cake

Chocolate bark cake

Peacock cake and cupcakes

36 comments on “Easy Galaxy Cake {Buttercream Icing}”

  1. Loved the cake as well the theme.5 stars

  2. Will make this cake for my grandsons birthday in February! Thank you for the directions and tips! Hopefully, it will be a success!

  3. I used homemade cake and frosting, but loved your design!5 stars

Leave a Reply

Your email address will not be published. Required fields are marked *

Recipe Rating