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Rainbow cupcakes with homemade frosting

Rainbow Cupcakes Recipe

These are my favorite EASY Rainbow Cupcakes! Start with a box mix for the cupcake but make a homemade marshmallow buttercream frosting and FOUR different ideas for topping!
Course Dessert
Cuisine American
Keyword cupcake, rainbow
Prep Time 30 minutes
Cook Time 20 minutes
Total Time 50 minutes
Servings 12 cupcakes
Calories 128kcal
Author Dorothy Kern
Cost $9


For the Rainbow Cupcakes

  • 1 15 ounce box white cake mix , prepared with eggs, oil, and water called for on the box
  • Food coloring (red, orange, yellow, green, blue, purple (gel food coloring works best for vibrant colors)

Marshmallow Buttercream

  • 1/2 cup unsalted butter softened
  • 1 7 ounce jar marshmallow creme
  • 1 1/2 cups powdered sugar
  • 1 teaspoon vanilla
  • Pinch salt

For the Cupcake Toppers

  • 24 white chocolate Reese's Peanut Butter Cups or
  • 12 Airheads Extremes cut in half, or
  • rainbow sprinkles


Make the Cupcakes

  • Mix the cake batter according to the recipe or box directions. Line your muffin tins with cupcake liners.
  • Divide your batter evenly among six bowls. Add food coloring to each bowl, one for each color of the rainbow (red, orange, yellow, green, blue, purple). Stir to combine.
  • You are going to layer the cupcakes into the liners in a reverse rainbow, so the purple is on the bottom and the red is on the top. To make this easier to do, place each color in a separate quart-sized Ziploc bag. Seal the bag almost all the way, leaving about 1/2" open for air to escape. Snip off a tiny corner and place a small amount in each cupcake liner, starting with purple (use just enough to cover the bottom of the liner). Repeat with the remaining colors in this order: blue, green, yellow, orange, red.
  • Bake according to box directions. Let cool completely.

Make the frosting

  • Beat butter and marshmallow creme together until smooth, then mix in powdered sugar, vanilla and salt. Frost cupcakes as desired (I like using a 1M tip).

Topping the cupcakes

  • Leave plain with the frosting.
  • Add rainbow sprinkles.
  • Place an Airhead Extreme in a rainbow arch on top.
  • Place a white chocolate peanut butter cup on top, frost it with frosting and sprinkle with sprinkles (like it's a mini cupcake ton top).
  • Store cupcakes in refrigerator to set frosting (it's a bit fluffy and will collapse if it's not set).



Serving: 1cupcake | Calories: 128kcal | Carbohydrates: 15g | Protein: 1g | Fat: 8g | Saturated Fat: 5g | Cholesterol: 20mg | Sodium: 2mg | Sugar: 15g | Vitamin A: 236IU | Calcium: 2mg