Rainbow Cakes. Listening To Flight Of The Conchords.

Rainbow Cakes

rainbow gif

I love Rainbow Cakes. (Like this one, this one, this one and these. Oh…pancakes, too.)

My son requested a Rainbow Cake for his birthday. I wanted to try something new. Cue in these beautiful cakes.

In addition to the rainbow layers, a little twist gives them a cubed color action.

The recipe for white cake produces a sturdy, yet delicious, cake which makes handling it pretty easy when making the surprise inside.
Rainbow Cakes
Rainbow Cakes


2 recipes White Cake (recipe follows)
Red, orange, yellow, purple, blue, and green gel food coloring
2 recipes Basic Buttercream (recipe follows)


1. Prepare the white cake batter.

2. Divide the batter evenly among 6 bowls. Add 10 drops of each color of gel.

3. Bake each layer in a 6 inch cake pan (Baking time is about 25 minutes. Remove from oven when tester inserted in centers comes out clean.) Cool layers completely.

Note: I only have three of the 6 inch cake pans, so had to bake the remaining three colored cakes when the first batch were cooled.

4. Level all of the cakes so they are the same height. This is important so that the rainbow inside the completed cake matches up correctly.

Note: I made the cakes one day ahead and wrapped in cling film when cooled.

5. Prepare the buttercream.

6. Place 1/2 cup of icing in a bowl and mix in enough orange food color to match the orange cake. Repeat to make yellow, blue and green buttercream.

7. Place the red layer on a cake plate and frost top with a thin layer of the orange buttercream. Do not spread icing all the way to the edge.
Rainbow Cakes
Rainbow Cakes

8. Add the orange cake layer and spread top with a thin layer of the yellow buttercream.
Rainbow Cakes

9. Add the yellow cake layer.

10. Repeat steps 7 through 9 to create a second cake with the purple, blue and green layers using the blue and green buttercream.
Rainbow Cakes

11. Gently push a 2 inch round cookie cutter into the center of one of the cakes to use as a cutting guideline. Use a long, sharp, thin knife to slice all the way through the cake and cut out a cylinder from the center. Repeat on the other cake. Place cakes on their sides and gently push out the cylinder using your fingers. Replace the cylinder from one cake with the cylinder from the other cake.
Rainbow Cakes
Rainbow Cakes
Rainbow Cakes

Note: The easiest way to remove the cylinders is to start with a well chilled cake. I was impatient, but had luck with my warm, July kitchen cake cylinders. I just had to use my hands to even up the layers before frosting them since they got a little jostled when I turned the cake on side to remove the cut out column.

12. Crumb coat the cakes with the uncolored icing and chill.
Rainbow Cakes

13. Using a small offset spatula, cover the cakes in a smooth coat of the white buttercream.

14. Divide the remaining icing equally among 6 bowls and tint with each of the six colors. Fill six pastry bags with the icings.

15. Insert a star decorating tip into a pastry bag. Create a pattern of stripes down one cake. (They were supposed to be herringbone stripes, but I did the best I could with my icing which was getting runny from the very warm kitchen. I ended up piping onto the cake while it was on a shelf in the refrigerator!)

16. On the second cake, pipe out rings of stars or scallops on the top of the cake in rainbow order, starting at the center.

Makes 2 (three layer) 6-inch cakes.

White Cake


3 cups cake flour
1 tablespoon baking powder
1/2 teaspoon table salt
1 cup milk
5 large egg whites
1/4 teaspoon almond extract
1 1/4 teaspoons vanilla extract
2 cups sugar
1 cup unsalted butter, softened


1. Heat oven to 350℉. Grease cake pans.

2. Sift together the flour, baking powder and salt.

3. In bowl of electric mixer, with the paddle attachment, cream butter and sugar on medium speed for 2 minutes or until light and fluffy.

4. In a large measuring cup, combine the milk, vanilla and almond.

5. Add one third of flour mixture to the butter mixture and blend on low for 30 seconds. Add 1/2 of milk mixture and blend until just combined. Add in half of the remaining flour mixture and blend until just combined. Add the remaining milk mixture and blend for a few seconds. Finally, add the remaining flour mixture and blend just until the ingredients are incorporated.

6. Pour the batter into a large bowl and clean the mixing bowl. Switch to the whisk attachment.

7. Add egg whites to the mixing bowl and beat on medium-high until firm peaks form.

8. Fold egg whites into the cake batter.

9. Pour batter evenly between the prepared cake pans.

10. Bake until tester inserted in the center comes out clean, 27 to 30 minutes.

11. Allow cake to cool to room temperature.

Makes 3 (6 inch) cake layers or 2 (8 inch) cake layers

Basic Buttercream


1/2 cup unsalted butter, softened
1/2 cup shortening
2 teaspoons vanilla
Pinch of salt
7 cups confectioners’ sugar
1/4 cup milk


1. Cream butter, shortening, vanilla and salt in a large mixing bowl using the paddle attachment.

2. Add confectioners’ sugar 1 cup at a time, alternating with the milk. If icing is too thick, add more milk. If too thin, add more confectioners’ sugar.

Note: This is a very sweet icing. I used about 5 cups of confectioners’ sugar. This was good to frost the cake. I had to add a bit more sugar to thicken the icing enough for piping.

Recipes from Surprise-Inside Cakes by Amanda Rettke
Rainbow Cakes
Rainbow Cakes
Rainbow Cakes
Rainbow Cakes
Rainbow Cakes
Rainbow Cakes

I saw Flight Of The Conchords in concert this past Saturday. They were hilarious. So funny and so incredibly talented.

And this one from the TV show.

“I’m the mother flippin'”

Check out Flight Of The Conchords on the band’s Website where you can buy their music. There are two more concert dates this week in LA. If you can get tickets, I highly recommend going to see these guys.


About I Sing In The Kitchen

Music obsessed cooking freak whipping up fab food one song at at time.
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4 Responses to Rainbow Cakes. Listening To Flight Of The Conchords.

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