# 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 - Gel food coloring (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
# Directions:
01 - Preheat oven to 350°F. Grease and line five 8 x 8-inch square baking pans or bake in batches if necessary.
02 - In a large bowl, beat the unsalted butter and granulated sugar together until light and fluffy. Incorporate eggs one at a time, then stir in vanilla extract.
03 - Whisk together flour, baking powder, and salt in a separate bowl.
04 - Alternately add the dry mixture and milk to the wet ingredients, starting and ending with the dry, mixing just until combined.
05 - Divide the batter evenly into five bowls and tint each with a different gel food coloring.
06 - Pour each colored batter into prepared pans, spread evenly, and bake for 20 to 25 minutes or until a toothpick inserted comes out clean.
07 - Allow cakes to cool in pans for 10 minutes before transferring onto wire racks to cool completely.
08 - Beat softened butter until creamy. Gradually add powdered sugar, vanilla, and salt, beating until fluffy. Add milk to reach desired consistency.
09 - Trim edges of cakes and slice each colored sponge into uniform 1 ¼-inch squares.
10 - Arrange sponge squares in alternating colors on a large tray using thin layers of buttercream to adhere squares. Build layers to create a quilted appearance.
11 - Apply a thin layer of buttercream to the top and sides, smoothing the surface. Optionally, pipe lines with buttercream to enhance the patchwork effect.
12 - Refrigerate the assembled cake for 30 minutes before slicing and serving.