# What You'll Need:
→ Sponge Cake
01 - 2 ¾ cups all-purpose flour
02 - 1 ½ cups granulated sugar
03 - 2 ½ teaspoons baking powder
04 - ½ 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 ½ cups unsalted butter, softened
11 - 4 cups powdered sugar
12 - 3 to 4 tablespoons milk
13 - 2 teaspoons vanilla extract
14 - Pinch of salt
# How-To Steps:
01 - Preheat oven to 350°F. Grease and line five 8 x 8-inch square baking pans or prepare to bake in batches.
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 stir in vanilla extract.
03 - In a separate bowl, whisk together all-purpose flour, baking powder, and salt.
04 - Add flour mixture and milk alternately to wet ingredients, beginning and ending with the flour mixture, mixing just until combined.
05 - Divide batter evenly into five bowls and tint each with a different color using food coloring gels.
06 - Pour each colored batter into prepared pans, spreading evenly. Bake 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 before transferring to wire racks to cool completely.
08 - Beat butter until creamy. Gradually add powdered sugar, vanilla extract, and salt, continuing to beat until fluffy. Add milk as needed to reach desired consistency.
09 - Trim edges and cut each colored sponge into uniform 1¼-inch squares.
10 - Arrange squares on a large tray in alternating colors to create a patchwork pattern, adhering squares with thin buttercream layers. Build successive layers for a quilted effect.
11 - Coat top and sides with a thin buttercream layer, smoothing the surface. Optionally, pipe decorative lines to enhance the patchwork design.
12 - Refrigerate assembled creation for 30 minutes prior to slicing and serving.