# Needed Ingredients:
→ 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 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 to 4 tablespoons milk
13 - 2 teaspoons vanilla extract
14 - Pinch of salt
# Preparation Steps:
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 - Beat unsalted butter and granulated sugar in a large bowl until light and fluffy. Add eggs one at a time, then incorporate vanilla extract.
03 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt.
04 - Alternately add flour mixture and whole milk to the butter mixture, beginning and ending with flour. Mix until just combined.
05 - Divide batter evenly into five bowls. Tint each with a different food coloring gel to achieve vibrant hues.
06 - Pour each colored batter into prepared pans and spread evenly. Bake for 20 to 25 minutes or until a toothpick inserted comes out clean.
07 - Allow cakes to cool in the pans for 10 minutes, then turn out onto wire racks to cool completely.
08 - Beat unsalted butter until creamy. Gradually add powdered sugar, vanilla, and salt, continuing to beat until fluffy. Add milk slowly to reach desired spreading consistency.
09 - Trim edges and slice each colored sponge into uniform 1 1/4 x 1 1/4 inch squares.
10 - Arrange sponge squares on a large tray in an alternating color pattern to form a patchwork. Use a thin layer of buttercream to adhere squares together. Build multiple layers maintaining the quilted effect.
11 - Apply a thin layer of buttercream over the assembled cake, smoothing the top and sides. Optionally pipe buttercream lines to enhance the patchwork appearance.
12 - Refrigerate the assembled cake for 30 minutes to set before slicing and serving.