# What's Needed:
→ Vanilla Cake
01 - 3 cups all-purpose flour
02 - 2 1/2 teaspoons baking powder
03 - 1/2 teaspoon salt
04 - 1 cup unsalted butter, room temperature
05 - 2 cups granulated sugar
06 - 4 large eggs, room temperature
07 - 1 tablespoon vanilla extract
08 - 1 1/4 cups whole milk
→ Buttercream
09 - 2 cups unsalted butter, room temperature
10 - 6 cups powdered sugar, sifted
11 - 2 teaspoons vanilla extract
12 - 3 to 4 tablespoons heavy cream or milk
13 - Teal gel food coloring
→ Geode Decoration
14 - 2 cups rock sugar crystals (clear or white)
15 - Teal gel food coloring
16 - Edible gold leaf or gold luster dust
17 - Clear alcohol (such as vodka) for painting
→ Assembly
18 - Simple syrup (optional, for moistening cake layers)
# How To Make It:
01 - Preheat oven to 350°F. Grease and line three 8-inch round cake pans with parchment paper.
02 - Whisk together all-purpose flour, baking powder, and salt in a mixing bowl.
03 - In a large bowl, cream unsalted butter and granulated sugar until mixture is light and fluffy.
04 - Beat in eggs one at a time, then mix in vanilla extract until combined.
05 - Alternate adding dry ingredients and whole milk to the butter mixture, beginning and ending with dry ingredients. Mix until smooth.
06 - Divide batter evenly between prepared pans. Bake for 28 to 32 minutes, or until a toothpick inserted in the center comes out clean.
07 - Let cake layers cool in pans for 10 minutes, then transfer to wire racks to cool completely.
08 - Beat unsalted butter until creamy. Gradually add powdered sugar, then incorporate vanilla extract and heavy cream as needed for spreadable consistency.
09 - Tint most buttercream with teal gel food coloring, reserving a portion uncolored for crumb coating.
10 - Place rock sugar crystals in a bowl. Add a few drops of teal gel food coloring and gently mix until evenly colored. Allow sugar crystals to dry if damp.
11 - Level cake layers as needed. Brush each layer with simple syrup if desired for additional moisture.
12 - Stack cake layers, spreading a thin layer of buttercream between each.
13 - Cover cake with a thin layer of uncolored buttercream to seal crumbs. Chill the coated cake for 20 minutes.
14 - Frost the chilled cake evenly with teal buttercream. Smooth the sides and top with an offset spatula.
15 - Using a serrated cake knife, carve a wedge or slice into the side of the cake to form the geode cavity.
16 - Apply a thin layer of buttercream inside the carved cavity. Press colored sugar crystals into the buttercream, using lighter crystals centrally and darker toward the edges for depth.
17 - Decorate the exposed edge of the geode with edible gold leaf or paint with gold luster dust mixed with clear alcohol, using a food-safe paintbrush for a metallic finish.
18 - Add additional gold accents and place a graduation topper on the cake if desired. Serve and enjoy.
