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These galactic swirl cupcakes could not be any easier because we use a doctored cake mix recipe using Duncan Hines white cake mix to create a light, fluffy, and tender cupcake that pairs perfectly with homemade American buttercream. You can customize these any color you would like. Made in partnership with Duncan Hines using their Perfectly Moist Classic White cake mix.

These cupcakes are out of this world! Moist, fluffy, tender, and delicious. They are easy as can be because we use a cake box mix as the shortcut for our dry ingredients. These Galactic Swirl Vanilla Cupcakes can be made light themed like the milky way using white and bright colors like in this post, or you can opt for a darker galaxy theme using black and deeper color tones.

I am so excited to share these cupcakes with you all. I partnered with Duncan Hines to bring these delicious cupcakes to life. These are the perfect cupcakes to make with your kids or as a family. Not only do we keep things simple with the help of boxed cake mix, but we also jazz it up a bit with tricolor swirl American buttercream and fun toppings like sprinkles, edible glitter, and cherries! My favorite cupcake decorating tips include Wilton’s 8B, 1M, and 2D.

Ingredients

Duncan Hines White Cake Mix – We use Duncan Hines White Cake Mix which takes care of our dry ingredients.
Buttermilk – Buttermilk is tangy and adds so much flavor and moisture to any cake or cupcake. If you do not have buttermilk on hand, which I myself never do, you can make it yourself by adding 1 tablespoon of white vinegar or lemon juice to 1 cup of milk. Let it sit for a few minutes and your milk will start to curdle and thicken, just like buttermilk! I literally do this ALL the time…actually anytime I need buttermilk, this is exactly what I do!
Greek Yogurt – You can also use sour cream if you do not have plain or vanilla greek yogurt on hand. Yogurt keeps the cupcake light and fluffy, while also adding moisture.
Egg Whites – Helps to keep the cupcakes light in texture and also light in color. I prefer only using egg whites in white cake recipes.
Oil – You can use vegetable oil or canola oil in this recipe. These are neutral oils and will not change the flavor, but rather help us out with a beautifully moist cupcake. Oil is our liquid fat component that helps to keep the cake tender and incredibly moist.
Vanilla Extract – For that extra vanilla flavor we all know and love.
Unsalted Butter – We use unsalted butter in our American buttercream frosting. When it comes to frosting, use the best butter you can because it will really make the difference in taste and texture. The only difference between unsalted butter and salted butter is the salt content. If you only have salted butter on hand, I would not add any extra salt into the buttercream until you taste it. It likely will not need it.
Powdered Sugar – Also known as confectioner’s sugar here in the United States. This is our sugar that we add into the frosting to give it that sweet American buttercream flavor. It will also stiffen and help shape the frosting. American buttercream does firm up and crust in the refrigerator or when left at/below room temperature. This frosting is sweeter than some other variations, but it is very customizable, is easy to dye different colors, and is super easy to pipe and decorate with. It is the frosting all kids know and love, and some adults might find it too sweet. I personally use a smaller ratio between the butter and sugar to avoid having my American buttercream too sweet. But, you are eating cake after all and American buttercream is classic and also what most people expect at a birthday party!
Heavy Whipping Cream – You can also use milk if that is all you have, but I recommend using heavy cream or even half & half to help your buttercream come together. Heavy cream helps the frosting become uniform, smooth, creamy, and the perfect consistency. You do not need a lot. I recommend adding in a tablespoon at a time until you reach your desired consistency. You can always add more if needed. Tip: If you thin your buttercream too much, add in a little more powdered sugar ¼ cup at a time until you regain your desired thickness.
Salt – A little bit of salt can go along way! It helps tame the sweetness. You won’t taste the salt, it just levels out the sweet!

Galactic Swirl Vanilla Cupcakes

Meg

Easy vanilla cosmic themed cupcakes! These cupcakes come together in less than an hour and are super tender, moist, and packed with vanilla flavor.

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Prep Time 10

Cook Time 18

Frosting & Decorating Time 25

Total Time 53

Course Dessert

Cuisine American

Ingredients

Cupcakes

1 box Duncan Hines Classic White cake mix
4 large egg whites
¼ cup plain greek yogurt ((or sour cream))
1 cup buttermilk
⅓ cup vegetable or canola oil
2 teaspoon vanilla extract

Vanilla American Buttercream

1 ½ cups unsalted butter ((3 sticks))
6-7 cups powdered sugar
3-5 tablespoon heavy whipping cream
1 tablespoon vanilla extract
pinch of salt

Supplies & Decorations

open star piping tip and piping bag
plastic wrap
edible glitter
star sprinkles and/or sprinkles of choice
gel food coloring
cupcake liners

Instructions

FOR THE CUPCAKES

Preheat oven to 325 degrees Fahrenheit and fill muffin pan with cupcake liners
Beat room temperature buttermilk, egg whites, oil, sour cream, and vanilla together until uniform
Add in cake mix and beat with a hand mixer for 1 – 2 minutes until combined. Avoid overmixing!
Divide cake batter into 3 bowls evenly. Dye one part blue, another part purple, and the third part white (or leave plain if you do not have white food gel).
Spoon in each color into the tins alternating the colors as you go. Fill cups ⅔ of the way full.
Bake for 18-20 minutes until a toothpick comes out clean.

Vanilla American Buttercream

In a stand mixer, beat room temperature butter until light and fluffy, around 2 minutes. You can also use a hand mixer but may need to beat the butter longer.
With your mixer on the lowest speed, add in the powdered sugar in four increments, mixing well in between to thoroughly combine. Alternate adding in 1T of heavy whipping cream in between increments. You may need anywhere from 3 to 5 tablespoons of heavy whipping cream to help the frosting come together smoothly. If frosting is too stiff, add in more heavy whipping cream one tablespoon at a time. If too loose, add in more powdered sugar a quarter cup at a time.
Once all the powdered sugar has been added, whip for an additional minute on high speed.
Scrape down the frosting from the sides of the mixing bowl, add in vanilla and salt. Whip for an extra couple minutes on high speed to ensure buttercream is uniform.
Split buttercream into three bowls, coloring each part just like you did the batter. One part blue, one part purple, one part white. This is when I love using a rubber spatula to smooth the buttercream and rid the air bubbles by adding in the gel coloring and then using your spatula push and smooth the frosting on the sides of the bowl.
To create a tri-color swirl, spread out a piece of plastic wrap on your counter. Pipe or spoon on buttercream in rows alternating colors. Roll up plastic wrap and twist the ends closed. Cut off a half inch at one end of the frosting log. Put open end down into a piping bag fitted with an open star tip.
Swirl buttercream frosting onto each cupcake. Top with star sprinkles, sanding sugar, edible glitter, and a sparkle cherry if desired.