# List of ingredients:
→ Sponge Cake
01 - 2 5/8 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 1/8 cups 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
# How to make it:
01 - Preheat the oven to 350°F. Grease and line five 8 x 8-inch square baking pans, or bake in batches if fewer pans are available.
02 - Using an electric mixer, cream the butter and sugar until light and fluffy. Add eggs one at a time, beating well after each addition, then incorporate vanilla extract.
03 - In a separate bowl, whisk together the flour, baking powder, and salt.
04 - Alternately add the flour mixture and milk to the creamed ingredients, starting and ending with the flour mixture. Mix until just combined to avoid overmixing.
05 - Divide the batter evenly into five bowls. Tint each with a different color using food coloring gels.
06 - Pour each colored batter into the prepared pans and spread evenly. Bake for 20 to 25 minutes, or until a toothpick inserted in the center comes out clean.
07 - Allow the cakes to cool in their pans for 10 minutes, then transfer to a wire rack to cool completely.
08 - Beat the butter until creamy. Gradually add powdered sugar, vanilla extract, and a pinch of salt, beating until fluffy. Add milk in small increments until the frosting reaches desired consistency.
09 - Trim the edges of each colored cake and slice into uniform 1 1/4-inch squares.
10 - Arrange the cake squares in alternating colors on a large serving tray, using a thin layer of buttercream between squares to adhere them. Build layers to form a colorful patchwork pattern.
11 - Apply a thin layer of buttercream over the top and sides, smoothing the surface. Optionally, pipe buttercream lines to accentuate the patchwork design.
12 - Refrigerate for 30 minutes to set before slicing and serving.