Make This Easy Rainbow Layer Cake for St. Patrick's Day

This St. Patrick's Day cake has it all — a rainbow in the middle and a pot of gold on top.

February 16, 2021
rainbow layer cake

Rainbow Cake

Baking colored cakes can be tricky – the cake may go in one color and come out a very different color. Why not avoid the trial and error by using rainbow colored icing to create a rainbow cake instead? Add sparkling gold sanding sugar on the top as a special added touch.

Photo by: Ellen Foord

Ellen Foord

Baking colored cakes can be tricky – the cake may go in one color and come out a very different color. Avoid the trial and error by opting for colored icing instead of dyes, and you'll get the same look with less hassle. For a little luck-of-the-Irish touch, create a sparkling gold sanding sugar top featuring a four-leaf clover in the center. We made a mini version for this recipe, but the technique can be used for any size cake.

Materials Needed

  • white cake (either from a recipe or box mix)
  • icing in each color of the rainbow
  • white frosting
  • gold sanding sugar
  • knife
  • icing spatula
  • mesh sieve

Bake and Cut Cake

Start by baking a white cake using any recipe or box mix. Allow it to fully cool. Next, cut off the dome top of the cake (Image 1). Discard or set aside for snacking. Cut the cake into several thin layers using a sharp serrated knife (Image 2). Lay the first layer in the center of a plate.

Apply Icing

Apply a layer of purple icing to the top of the cake layer (Image 1). Next, top with another layer of cake and apply a layer of blue icing. Continue the icing/cake layering process until each color of the rainbow is present and place the topmost layer of cake on the red icing (Image 2). Chill in the fridge to firm.

Apply Frosting

Mix a batch of white frosting, or use store-bought for convenience. Crumb coat the cake with a thin layer of white frosting. Chill the cake. Once the crumb coat is set, apply a thicker coat of frosting and use your spatula to create texture.

applying frosting

Apply Frosting

Crumb coat the cake with a thin layer of white frosting. Chill again.

Photo by: Ellen Foord

Ellen Foord

Create Clover

Pour a small amount of sanding sugar into a fine-mesh sieve. Then, holding the paper template over the center of the cake, shake the sieve gently to sprinkle sugar over the top of the cake (Image 1). Remove the template to reveal the clover (Image 2).

Cut and Enjoy

Cut into the cake with a sharp knife to reveal the rainbow layers. Don't forget to make a lucky wish!

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