# 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 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
# Method:
01 - Preheat oven to 350°F. Grease and line five 8 x 8 inch square pans or bake in batches if pans are limited.
02 - In a large bowl, cream butter and granulated sugar until light and fluffy. Add eggs one at a time, beating well after each addition, then incorporate vanilla extract.
03 - Whisk together flour, baking powder, and salt in a separate bowl.
04 - Alternately add flour mixture and milk to the wet ingredients, starting and finishing with flour. Stir until just combined without overmixing.
05 - Evenly divide batter into five bowls, tint each with a different gel food coloring to achieve vibrant shades.
06 - Pour each colored batter into prepared pans and smooth surface. Bake for 20 to 25 minutes or until a toothpick inserted in the center comes out clean.
07 - Allow cakes to cool in their pans for 10 minutes before transferring to a wire rack to cool completely.
08 - Beat softened butter until creamy. Gradually add powdered sugar, vanilla extract, and salt, beating until fluffy. Adjust consistency with milk as needed.
09 - Trim cake edges and slice each colored sponge into uniform 1 1/4 inch squares.
10 - Arrange sponge squares in alternating colors on a large tray, adhering them with a thin layer of buttercream. Build layering by repeating the pattern for a quilted appearance.
11 - Apply a thin, even layer of buttercream over the assembled block, smoothing the surface. Optionally, pipe buttercream lines to enhance the patchwork design.
12 - Refrigerate the assembled cake for 30 minutes to set before slicing and serving.