# What You Need:
→ Vanilla Sponge Cakes
01 - 4 1/2 cups all-purpose flour
02 - 3 1/2 teaspoons baking powder
03 - 1/2 teaspoon salt
04 - 2 1/2 cups granulated sugar
05 - 1 1/2 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 - 1/2 cup whole milk or heavy cream
12 - 2 tablespoons vanilla extract
13 - Pinch of salt
14 - Gel food coloring, optional
→ Decoration
15 - Balloon cake toppers, store-bought or homemade
16 - Edible confetti or sprinkles, optional
# Steps:
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 until evenly combined.
03 - In a large bowl, beat butter and sugar together until light and fluffy, approximately 3 to 5 minutes.
04 - Add eggs one at a time, beating well after each addition. Mix in vanilla extract until fully incorporated.
05 - With the mixer on low speed, alternate adding the flour mixture and milk in three additions, beginning and ending with flour. Mix until just combined, avoiding overmixing.
06 - Divide the batter evenly between the 8-inch and 6-inch pans. Tap pans gently 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 proceeding.
09 - Beat butter until creamy. Gradually add powdered sugar, beating well. Mix in vanilla, salt, and milk or cream one tablespoon at a time until smooth and spreadable. Tint with food coloring if desired.
10 - Level cake tops if needed. Place one 8-inch layer on a cake board, spread a layer of buttercream, and top with the second 8-inch cake. Repeat the layering process for the 6-inch cakes.
11 - Apply a thin crumb coat of buttercream to each cake tier. Chill for 20 minutes to set.
12 - Frost both cake tiers smoothly with remaining buttercream. Stack the 6-inch cake tier centered on top of the 8-inch tier, using dowels or straws for structural support if needed.
13 - Arrange balloon toppers on the cake and add edible confetti or sprinkles as desired.
