# What You'll Need:
→ 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 graduation colors
→ Decoration
15 - Balloon cake toppers, store-bought or homemade with food-safe sticks and mini balloons
16 - Edible confetti or sprinkles, optional
# How to Make It:
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 distributed.
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 to the butter mixture, beating well after each addition. Mix in vanilla extract until fully combined.
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 among the four cake pans, distributing equal amounts to each. 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, 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 at room temperature.
09 - Beat softened butter until creamy. Gradually add powdered sugar, beating well after each addition. Mix in vanilla extract, 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 for even stacking. Place one 8-inch layer on a cake board, spread a layer of buttercream, and top with the second 8-inch cake. Repeat the process for the 6-inch cakes.
11 - Apply a thin crumb coat of buttercream to each cake tier, sealing in loose crumbs. Refrigerate for 20 minutes until 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 - Crown the cake with balloon toppers and scatter edible confetti or sprinkles as desired for festive presentation.