Confetti Cake with Rainbow Sprinkles

Course Dessert

Cuisine American

Prep Time 35

Cook Time 25

Decorating Time 45

Total Time 1 45

Servings 1 8" cake (16 slices)

2-8” (20 cm) round cake pans
Digital scale (or dry measuring cups, liquid measuring cups, and measuring spoons)
Stand mixer with paddle attachment (or large bowl with hand mixer)
Sifter
Parchment paper circles
Non-stick baking spray
Medium bowl
Whisk
Microplane zester
Silicone spatula
Stand mixer shield (optional)
Toothpick
Wire rack
Cardboard cake board (optional)
Cake stand (optional)
Turntable (optional)
Offset spatula (optional)
Cake comb (optional)
Piping bags (optional)
Decorative tips (optional)

3¼ cups (325g) cake flour, sifted
1 Tbsp + ¼ tsp (14g) baking powder
¾ tsp (4.5g) salt
2 sticks (1 cup or 227g) unsalted butter, softened
1½ cups (300g) granulated sugar
6 large (180g) egg whites
1 tsp (2g) finely grated lemon zest
2 tsp (8.5g) vanilla extract
1⅓ cups (320g) whole milk
½ - ¾ cup (85-128g) rainbow sprinkles + 1-2 Tbsp for optional decoration
9 cups (1.35kg) buttercream or frosting of choice (I am using Vanilla Italian Meringue Buttercream)

Begin by preheating the oven to 350°F/180°C with the oven rack in the middle. Prepare two 8-inch round cake pans by greasing the bottom and sides of the pan (I like to use Crisco vegetable shortening, but you could also use butter or baking spray). Place a piece of parchment paper in the bottom of each pan, lightly grease the parchment paper, and then dust the inside of the pan with flour. Dump any excess flour from the pan.

Sift together the dry ingredients (i.e., flour, baking powder, and salt) into a medium bowl. Whisk to combine and then set aside.
In the bowl of the stand mixer (or a large bowl if using a hand mixer), use the paddle attachment to beat the softened butter at medium speed until creamy and smooth. This should take approximately 30 seconds. Increase the speed to high and gradually add the sugar. Mix for approximately 2 minutes until the mixture is light and fluffy.
Reduce the speed to low and add the egg whites, one at a time. Make sure to beat well after each addition. It’s normal for the mixture to look a little curdled at this point.
Next, beat in the lemon zest and vanilla extract. Scrape the bowl with a spatula to ensure all ingredients are incorporated into the batter.
Add the dry ingredient mixture in three additions alternating with the milk. The milk sometimes splashes when adding it, so add it slowly or use a stand mixer shield (if you have one). Only mix until the flour is just incorporated.
Add the rainbow sprinkles and use a spatula to fold them gently into the batter.
Evenly divide the batter between the two prepared pans and smooth the tops.

Bake the cake for 25-30 minutes or until a toothpick inserted into the cake comes out clean. Cool the cakes in the pans on a cooling rack for 15 minutes before turning the cakes out to finish cooling completely.

Use a long, serrated knife to cut each layer into two for a total of 4 layers. Place the flat side of one layer on a cake board, cake stand, or serving plate. Then, place it on top of a turntable (if you have one). This will make it easier to decorate the cake on all sides and get smooth frosting.
Add a layer of frosting or buttercream (I'm using Vanilla Italian Meringue Buttercream) and use an offset spatula to spread the buttercream until smooth. If you don’t have an offset spatula, you can use a butter knife instead.
Top with another cake layer and add the buttercream on top. Repeat one more time and finish stacking the cake by placing the last cake layer upside down so the top of the cake has sharp corners and a flat top.
Frost the sides and top of the cake with more buttercream and use an offset spatula to smooth the frosting OR use a cake comb to add a patterned design. Reserve approximately 1 cup of buttercream if you want to add piped decorations to the top or bottom of the cake.

Place the remaining buttercream into a piping bag fitted with a 1M tip. Pipe a continuous swirl around the top of the cake and add a generous amount of rainbow sprinkles to the top and sides.

Keep the confetti cake in an airtight container (e.g., a cake keeper or a covered cake plate). It will stay fresh up to 3 days at room temperature or up to 5 days in the fridge. If you store the cake in the fridge, allow it to come to room temperature before serving (i.e., let it sit at room temperature for 20-30 minutes before serving). The butter in the cake will harden in the fridge so it will have a dry and firm texture if eaten directly from the fridge.