# What you'll need:
→ Sponge Cake
01 - 3 cups all-purpose flour
02 - 1 1/2 cups granulated sugar
03 - 2 1/2 teaspoons baking powder
04 - 1/2 teaspoon salt
05 - 1 cup unsalted butter, softened
06 - 4 large eggs
07 - 1 cup whole milk
08 - 2 teaspoons vanilla extract
09 - Food coloring gels (red, yellow, green, blue, purple)
→ Buttercream Frosting
10 - 1 1/2 cups unsalted butter, softened
11 - 4 cups powdered sugar
12 - 3–4 tablespoons milk
13 - 2 teaspoons vanilla extract
14 - Pinch of salt
# Method:
01 - Preheat oven to 350°F. Grease and line five 8 x 8-inch square baking pans, or plan to bake in batches if pans are limited.
02 - In a large bowl, beat butter and sugar together until light and fluffy. Add eggs one at a time, beating well after each addition, then blend in vanilla extract.
03 - In a separate bowl, whisk together flour, baking powder, and salt until evenly mixed.
04 - Alternately add the flour mixture and milk to the butter mixture, beginning and ending with the flour mixture. Stir until just combined.
05 - Divide batter evenly into five bowls. Tint each portion with a different food coloring gel to desired vibrancy.
06 - Pour each colored batter into prepared pans and spread evenly. Bake for 20–25 minutes or until a toothpick inserted into the center comes out clean.
07 - Allow cakes to cool in pans for 10 minutes before turning them out onto wire racks to cool completely.
08 - Beat butter until creamy. Gradually add powdered sugar, vanilla extract, and salt, beating until fluffy. Add milk dropwise to reach desired spreading consistency.
09 - Trim edges from cooled cakes and slice each colored sponge into uniform 1¼ x 1¼-inch squares.
10 - On a large serving tray, arrange sponge squares in an alternating color pattern to create a patchwork effect. Use a thin layer of buttercream between squares to adhere them together, building multiple layers for a quilted look.
11 - Apply a thin, smooth layer of buttercream to the top and sides of the assembled cake. Optionally, pipe buttercream lines to emphasize the patchwork design.
12 - Refrigerate the cake for 30 minutes to firm up before slicing and serving.