# Components:
→ Sponge Cake
01 - 2 3/4 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 3/4 sticks 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 3/4 sticks unsalted butter, softened
11 - 4 cups powdered sugar
12 - 3 to 4 tablespoons milk
13 - 2 teaspoons vanilla extract
14 - Pinch of salt
# Directions:
01 - Preheat oven to 350°F. Grease and line five 8x8-inch square baking pans or prepare to bake in batches if limited.
02 - In a large bowl, cream softened butter and granulated sugar until light and fluffy. Beat in eggs one at a time, then stir in vanilla extract.
03 - Whisk together flour, baking powder, and salt in a separate bowl until combined.
04 - Alternate adding the flour mixture and milk to the creamed ingredients, starting and ending with the flour mixture, mixing until just incorporated.
05 - Divide batter evenly into five bowls. Tint each portion with a different food coloring gel.
06 - Pour each colored batter into prepared pans and spread evenly. Bake for 20 to 25 minutes, or until a toothpick inserted in the center comes out clean.
07 - Allow cakes to cool in pans for 10 minutes, then transfer onto wire racks to cool completely.
08 - Beat softened butter until creamy. Gradually add powdered sugar, vanilla extract, and salt, beating until fluffy. Add milk gradually to reach desired consistency.
09 - Trim cake edges and cut each colored sponge into uniform 1x1 inch squares.
10 - Arrange squares on a large tray in alternating colors to create a patchwork pattern. Use a thin layer of buttercream between squares to adhere them. Build layers alternating colors for a quilted effect.
11 - Apply a thin layer of buttercream to cover the top and sides, smoothing the surface. Optionally, pipe buttercream lines to enhance the patchwork design.
12 - Refrigerate assembled cake for 30 minutes before slicing and serving.