# Ingredient list:
→ Vanilla Sponge Cakes
01 - 4.5 cups all-purpose flour
02 - 3.5 teaspoons baking powder
03 - 0.5 teaspoon salt
04 - 2.5 cups granulated sugar
05 - 1.5 cups unsalted butter, room temperature
06 - 8 large eggs, room temperature
07 - 2 tablespoons pure vanilla extract
08 - 2 cups whole milk, room temperature
→ Buttercream Frosting
09 - 2 cups unsalted butter, room temperature
10 - 8 cups powdered sugar, sifted
11 - 0.5 cup whole milk or heavy cream
12 - 2 tablespoons vanilla extract
13 - Pinch of salt
14 - Gel food coloring, optional for school colors
→ Decoration
15 - Balloon cake toppers, store-bought or homemade with food-safe sticks
16 - Edible confetti or sprinkles, optional
# Step-by-step guide:
01 - Preheat oven to 350°F. Grease and line two 8-inch round cake pans and two 6-inch round cake pans with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
03 - In a large bowl, beat butter and sugar together using a mixer until light and fluffy, approximately 3 to 5 minutes.
04 - Add eggs one at a time to the butter mixture, beating well after each addition. Mix in vanilla extract until combined.
05 - With mixer on low speed, alternate adding the flour mixture and milk in three additions, beginning and ending with flour. Mix until just combined without overmixing.
06 - Divide batter evenly among the four prepared pans. Gently tap each pan on the counter to release air bubbles.
07 - Bake 8-inch cakes for 35 to 40 minutes and 6-inch cakes for 25 to 30 minutes, or until a toothpick inserted in the center comes out clean.
08 - Allow cakes to cool in pans for 10 minutes, then transfer to wire racks to cool completely before assembly.
09 - Beat butter until creamy. Gradually add powdered sugar, beating well after each addition. Mix in vanilla extract, salt, and milk or cream 1 tablespoon at a time until smooth and spreadable. Tint with gel food coloring if desired.
10 - Level cake tops with a serrated knife if needed. Place one 8-inch layer on a cake board, spread a layer of buttercream, and top with the second 8-inch cake layer.
11 - Repeat layering process with the two 6-inch cake layers, placing buttercream between them.
12 - Apply a thin crumb coat of buttercream to each assembled cake tier using an offset spatula. Refrigerate for 20 minutes to set.
13 - Frost both cake tiers with remaining buttercream using an offset spatula, creating smooth surfaces on all sides.
14 - Stack the 6-inch cake tier centered on top of the 8-inch tier. Insert cake dowels or straws through the base tier for structural support if needed.
15 - Top the two-tier cake with balloon toppers and scatter edible confetti or sprinkles as desired.
