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Rainbow Petal Cake

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  • Prep 45 min
  • Total 1 hr 45 min
  • Servings 16
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Everybody's day will get brighter when you surprise your guests with this delightful rainbow dessert! This fantastically colorful cake is a blast to decorate, and the result is a sweet treat that looks amazing and tastes even better. Break out this Rainbow Petal Cake recipe for birthday parties, holidays and other special occasions—or bake it up to make an average day extraordinary.
Updated May 31, 2023
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  • 2 boxes Betty Crocker™ Delights Super Moist™ Strawberry Cake Mix
  • 2 cups water
  • 1 cup vegetable oil
  • 6 eggs
  • Pink paste food color
  • Buttercream Frosting
  • 1 1/2 cups shortening
  • 1 1/2 cups butter, softened
  • 3 boxes (1 lb each) powdered sugar
  • 3 teaspoons vanilla
  • 1/4 to 1/3 cup milk
  • Pink, purple, orange, green, blue and yellow paste food colors


  • 1
    Heat oven to 350° F. Spray 3 (8-inch) round cake pans with cooking spray.
  • 2
    In large bowl, beat cake ingredients with electric mixer on low speed 30 seconds. Beat on medium speed 2 minutes. Pour batter into pans.
  • 3
    Bake 18 to 20 minutes or until cake springs back when touched lightly in center. Cool 10 minutes; remove from pans to cooling racks. Cool completely.
  • 4
    In large bowl, beat shortening and butter with electric mixer on medium speed until light yellow. On low speed, gradually beat in powdered sugar. Beat in vanilla. Add milk, 1 tablespoon at a time, beating until frosting is smooth. Beat on high speed until light and fluffy.
  • 5
    Place 3 cups frosting in separate bowl; stir in pink food color. Divide remaining frosting (about 1 cup for each color) among 5 bowls; tint with remaining food colors. Trim rounded tops off cakes to level, if needed. On serving plate, place 1 cake layer. Spread with pink frosting to within 1/4 inch of edge. Repeat with remaining cake layers. Spread thin layer of frosting on top and side of cake to seal in crumbs.
  • 6
    Spoon 1 color frosting into decorating bag fitted with #12 tip. Pipe row of straight dots on cake from top to bottom. Gently spread each dot with offset pastry knife, cleaning knife after each time. Repeat with remaining colors of frosting. Create another row of dots where frosting ends and spread each dot with knife. Repeat until whole cake is finished. When scallops end, add final row of dots to "seal" the seam. Pipe top of cake with one dot at a time; spread and then pipe again, creating a concentric circle.

Tips from the Betty Crocker Kitchens

  • tip 1
    Using paste or gel food colors (not liquid food colors) helps keep frosting from becoming too thin.
  • tip 2
    For easier removal of cakes from cake pans, line each cake pan with 8-inch round of cooking parchment paper; spray with cooking spray. Add cake batter, and bake as directed.
  • tip 3
    To make decorating easier, try using a revolving cake stand or cake turntable for this Rainbow Petal Cake recipe! You can find revolving cake stands at most craft stores or online. The rotating ability allows for you to turn the cake stand as you pipe on the frosting.


Nutrition Facts are not available for this recipe
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