The Quest for Rainbow Cake

The first book that MiniChef picked for our Book-Cook Project was Quest by Aaron Becker. He loves it and its prequel, Journey. (MiniChef "wrote" a sequel called Adventure...and then it turned out there actually is a sequel called Return. We haven't read it yet, but we're excited to!) He says he likes it because "there's a king and they get to draw cool creatures."

Since MiniChef is kind of obsessed with cake competition shows--ok, ok, we're both kind of obsessed with cake competition shows, and we watch them together...a lot--it makes a ton of sense that the first thing he wanted to make was a cake. The wordless book features two children, who we call Penelope and Harold. They each have their own crayon (Harold's is purple, naturally), and in the course of their quest to defeat an evil ruler and return the rightful king to his throne, they collect a rainbow of other crayons, which they use to color their world. 

MiniChef's specific request for this recipe was a rainbow-colored cake to go with the world-saving rainbow. And here's how we did it!

For the Cake
(Adapted from Cook's Illustrated)

1 cup whole milk, room temperature
6 large eggs, room temperature
2 teaspoons vanilla extract
2 1/4 cups cake flour
1 3/4 cups sugar
4 teaspoons baking powder
1 teaspoon salt
12 tablespoons unsalted butter, softened but still cool
Gel food coloring (your choice of colors)
You can use liquid food coloring instead, but gel creates deeper colors with fewer drops, and doesn't change the liquid content of the batter.

(Note: it's important that the eggs and milk are at room temperature, otherwise the batter will separate.)

Here are the steps I did myself before MiniChef joined me:

Separate the eggs--we'll be using only the egg whites. Put the yolks in the fridge to use for another project.

Preheat oven to 350 degrees, and adjust oven rack to the middle position. We're still getting used to having an electric oven, so this step was actually the most difficult! Grease two 9-inch round cake pans, line with parchment, grease again, and flour the pans. (You can also use three 8-inch round cake pans, if that's what you've got.)

My boy loves his...er, our KitchenAid.

Here are the steps we did together:

Pour your egg whites into a 2-cup liquid measuring cup, and mix in the milk and vanilla. 

Put dry ingredients (flour, sugar, baking powder, and salt) into the bowl of a stand mixer fitted with the paddle attachment, and mix on low speed for a few seconds, until just combined. Add the chilled butter one piece at a time, and mix on low for about one minute until you only see pea-sized pieces.

Add half of the milk/egg/vanilla mixture, increase speed to medium-high, and beat for about one minute, until light and fluffy. Turn speed down to medium-low, add remaining milk/egg/vanilla mixture, and mix for about 30 seconds. The batter might look slightly curdled, but that's ok! Don't fret--it's supposed to do that. Give the batter one stir by hand. Let your kid lick the paddle.

Divide batter evenly into six bowls. Set two bowls aside; these will stay white. Mix food coloring into each of the four other bowls to achieve the colors you've chosen. (We wanted red, orange, blue, and green. We experimented with how many drops of food coloring went into each bowl, and kept mixing until we liked the result.)

Decide which colors you want in each layer of cake: there should be two colored batters and one white batter in each. Drop your batters in random tablespoons into your prepared cake pans. Use a knife or skewer to "marble" the batter until the colors are mixed to your liking.

I did this part by myself too, because MiniChef isn't allowed to use the oven yet:

Put the pans in the oven and bake until a toothpick inserted in center comes out clean, about 20-25 minutes (18-22 minutes for 8-inch pans), rotating the pans halfway through baking. Let the cakes cool in the pans on a wire rack for ten minutes. Remove the cakes from the pans, and let cool in the refrigerator for at least 45 minutes. The colder the cake when frosting, the better.

For the Frosting(Adapted from Martha Stewart)

1 cup (2 sticks) unsalted butter, room temperature 6-8 cups confectioners' sugar1/2 cup milk1 teaspoon vanilla extract We did all of this together: Place the butter in the bowl of your electric mixer fitted with the whisk attachment, and cream until smooth and creamy. This will take two-three minutes or more. Look for the butter to lighten in color. With mixer on low, add six cups sugar, the milk, and the vanilla. Mix until light and fluffy. If the frosting isn't your desired consistency, keep adding sugar gradually until it's what you want. I did this part by myself: Frost the cake with your best method. I aspire to Joy the Baker's method of frosting; as it is, I put about 3/4 cup of frosting on the top of the blue/green layer and spread it with a butter knife. Place the second layer on top. Frost the whole cake with a light "crumb coat" and put in the refrigerator for at least 15 minutes. Take cake out of the fridge and frost as thick a layer as you'd like. We did this part together: Toss sprinkles all over the darn place! Here's what MiniChef has to say about the cake: "It was very yummy. I liked the frosting. My favorite part of making it was that we had fun making it. I got to lick the batter!" The cake will last for at least three days in the fridge. You will absolutely have more frosting than you'll need. I recommend storing the leftover frosting in airtight storage, taking it out about a half-hour before you want to use it again, and dunking either pretzels or graham crackers in it.