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Rainbow striped cake

Prep Time2 hrs
Cook Time45 mins
Resting time2 hrs
Total Time4 hrs 45 mins
Course: Dessert
Cuisine: American
Keyword: Cake


  • 3 Piping bags
  • Wilton 2D Tip
  • Bench Scraper
  • Striped comb


Vanilla Cake

  • 1 box cake mix
  • 1/4 cup butter
  • 1/4 cup vegetable oil
  • 4 large eggs
  • 1 cup milk
  • gel food coloring

Swiss Meringue Buttercream

  • 180 grams about 6 large egg whites
  • 360 grams granulated sugar
  • 450 grams unsalted butter room temperature cubed
  • 1 tsp vanilla


  • Gold Sprinkles
  • Gel Food Coloring


Vanilla Cake

  • Preheat oven to 350F and grease and flour three 6” cake rounds.
  • In a large bowl, add the cake mix and all the other ingredients, except for the food coloring. Mix well together.
  • Divide the batter in half - you only need 1/2 of the batter for the 3 cake layers.
  • Then divide the cake batter into 3 equal portions, and color each of them.
  • Pour each into prepared cake tins.
  • Bake for 20-25 minutes, until a toothpick inserted into the center comes out mostly clean.
  • Cool until ready to use.

Vanilla Swiss Meringue Buttercream

  • Place egg whites and sugar into the bowl of a stand mixer, whisk until combined. 
Place the bowl over a hot water bath on the stove and whisk constantly until the mixture is hot and no longer grainy to the touch or until it reaches a temperature of 165 degrees F on a candy thermometer. 
Place the bowl on your stand mixer and whisk on medium-high until the meringue is stiff and cooled (the bowl is no longer warm to the touch (approx. 5-10mins).
 Switch to a paddle attachment. Slowly add cubed butter and mix until smooth. Add vanilla and continue to whip until smooth.

Cake Assembly

  • Spread some buttercream on the cake board.
  • Place one layer of cake on a cake board and place it in the fridge for 5-10 minutes. This will help the cake stick to the cake board and not slip as you stack and frost.
  • Remove from the fridge.
  • Top with approximately 1/3 cup of frosting and spread evenly.
  • Repeat with remaining layers and apply a thin coat of frosting all over the cake for the crumb coat. Chill for 20mins.
 Frost with a generous layer of frosting and smooth the sides.
  • Place cake in the fridge for 30 minutes.
  • Once chilled, drag the striped comb to create ridges for the stripes.
  • Place cake in the fridge for another 45 minutes to 1 hour until buttercream is completely firm.
  • While the cake is in the fridge, color the buttercream for the stripes. Color 1/2 cup of frosting for each of the 4 colors - yellow, green, purple, and red. Place each color into separate piping bags.
  • Once the cake has chilled, remove from fridge and place on the cake turntable.
  • Pipe the ridges with the colored buttercream, ensuring ridges are filled.
  • Once all the ridges are filled, using a bench scraper smooth the buttercream, wiping the bench scraper after each swipe. Keep going until stripes are revealed.
  • Use the leftover buttercream and a 2D piping tip to create the top.
  • Once you're happy with the look, finish decorating the cake with a splatter of rose gold paint & gold sprinkles if desired.
  • Slice and serve at room temperature.