Rainbow Cake Recipe


Rainbow Cake RecipeThis festive Rainbow Cake is an impressive birthday party cake, made from a deceptively easy recipe. Even if you are a cake-decorating novice, you can handle this simple cake recipe. This is perfect for a St. Paddy's Day celebration (just don't expect to find a leprechaun at the end) or great for a spring party or a birthday party.


  • 1 box cake mix and accompanying ingredients needed to make cake
  • Bundt cake pan
  • 5 cups white decorator icing
  • red food coloring
  • orange food coloring
  • yellow food coloring
  • green food coloring
  • blue food coloring
  • violet food coloring
  • Wilton 1M tip (or another large star tip)
  • pastry bags
  • 10 inch round cake board (or cardboard)
  • decorative foil wrap
  • tape
  • serrated knife


Step 1: Make the cake batter according to package directions, and bake the cake in the Bundt pan according to the package directions.
Rainbow Cake Recipe - Step 1

Step 2: Turn the cake out onto a cooling rack to cool completely.
Rainbow Cake Recipe - Step 2

Step 3: While the cake is cooling color your icing like so:

  • color 2 cups of icing red using the red food coloring
  • color 1 cup of icing violet using the violet food coloring
  • color ½ cup of decorator icing orange using the orange food coloring
  • color ½ cup of decorator icing yellow using yellow food coloring
  • color ½ cup of decorator icing green using green food coloring
  • color ½ cup of decorator icing blue using blue food coloring

Step 4: Cover a 10 inch round cake board with decorative foil.

Step 5: Level the top of the cake with a serrated knife so it's flat.
Rainbow Cake Recipe - Step 5

Step 6: Cut the cake in half so you have a half moon for the rainbow.

Step 7: Put a little icing on the cake board in a half moon shape, where you’re placing the cake; this will act as a glue to keep the cake in place. Place the cake on the cakeboard over the icing, cut-side down.
Rainbow Cake Recipe - Step 7

Step 8: With a spatula, ice the back of the cake (the outside of the rainbow) up to the top, with red icing to seal up any cracks at the base of the cake.

Step 9: With a spatula ice the front of the cake (inside or the rainbow) with violet icing about half way up the side, as shown in the image below:
Rainbow Cake Recipe - Step 9

Step 10: Put the Wilton 1M tip on a pastry bag and fill the bag with red icing. Start placing rows of red icing stars over where you iced the cake with the red icing. To make the stars, hover the tip over the section of the cake you want to ice, squeeze the pastry bag gently and lift as you gently release. Make stars in rows, repeating your icing motion. Keep repeating the rows up to the top edge of the cake, and around the end.
Rainbow Cake Recipe - Step 10

Step 11: Switch the 1M tip to a pastry bag with orange icing and make a row of orange stars adjacent to the red at the top of the cake.

Step 12: Repeat the process to make rows of yellow, green, and blue stars, each adjacent to the next to form the rainbow. Don’t forget to continue the star rainbow onto the ends of the cake.
Rainbow Cake Recipe - Step 13

Step 13: Switch the 1 M tip to a pastry bag with violet icing, and fill in the bottom of the front of the cake with violet stars to complete the rainbow.
Rainbow Cake Recipe - Final

Note: If you need to feed a bigger crowd, you could add an iced 9 x 11 inch sheet cake to the bottom.

Want more cake decorating ideas?

Find more fabulous, kid-friendly ideas from Linette Gerlach at The Kid's Fun Review.