# Required Ingredients:
→ Cake layers
01 - 2 3/4 cups all-purpose flour
02 - 2 1/2 teaspoons baking powder
03 - 1/2 teaspoon baking soda
04 - 1/2 teaspoon fine salt
05 - 1 cup unsalted butter (2 sticks), room temperature
06 - 2 cups granulated sugar
07 - 4 large eggs, room temperature
08 - 2 teaspoons pure vanilla extract
09 - 1 1/4 cups whole milk, room temperature
10 - Blue gel food coloring — navy, royal and light blue tones
→ Vanilla buttercream
11 - 1 1/2 cups unsalted butter, room temperature
12 - 5 cups powdered sugar, sifted
13 - 2 teaspoons pure vanilla extract
14 - 3 to 4 tablespoons whole milk or heavy cream
15 - Pinch of fine salt
16 - Dark blue gel food coloring
→ Gold decoration
17 - Edible gold leaf or edible gold dust
18 - 1 to 2 tablespoons clear alcohol (vodka) or lemon extract, for diluting gold dust
# Preparation Steps:
01 - Preheat oven to 350°F (175°C). Grease and line three 8-inch round cake pans with parchment rounds and a light coating of butter or baking spray.
02 - Whisk together the flour, baking powder, baking soda and salt in a medium bowl until evenly combined; set aside.
03 - In the bowl of a stand mixer or a large bowl with a hand mixer, beat the butter and granulated sugar on medium-high speed until pale and fluffy, about 3 to 4 minutes.
04 - Add the eggs one at a time, beating well after each addition, then beat in the vanilla extract until homogenous.
05 - With the mixer on low, add the flour mixture and milk in three additions, beginning and ending with the flour, mixing only until just combined to avoid overworking the batter.
06 - Divide the batter evenly among three bowls. Tint each portion with gel food coloring to create a light, medium and dark blue gradient, adjusting intensity gradually.
07 - Divide each colored batter into the prepared pans, smoothing the tops with an offset spatula to an even thickness.
08 - Bake layers for 25 to 30 minutes, or until a toothpick inserted in the center comes out clean. Allow cakes to cool in pans for 10 minutes, then invert onto wire racks to cool completely.
09 - Beat the butter until creamy, then gradually add the sifted powdered sugar, mixing on low then increasing speed. Add vanilla, salt and enough milk or cream to reach a spreadable consistency.
10 - Reserve 1 cup of the plain buttercream for the crumb coat; tint the remaining buttercream with dark blue gel color for the final exterior coat.
11 - Level each cake layer if necessary. Place the darkest blue layer on the serving board, spread an even layer of buttercream, then stack the medium and light layers, pressing gently to align.
12 - Apply a thin crumb coat of the reserved plain buttercream over the entire assembly, smooth lightly, then chill the cake for 20 minutes to set the crumb coat.
13 - Cover the chilled cake with the dark blue buttercream, smoothing with an offset spatula or bench scraper. Blend in lighter blue tones toward the top to refine the ombré transition if desired.
14 - Adhere edible gold leaf directly to dry buttercream or brush diluted gold dust (gold dust mixed with vodka or lemon extract) in decorative streaks or along edges for accent.
15 - Return the decorated cake to the refrigerator to set for at least 30 minutes before serving. Bring to room temperature for 20 minutes before slicing.
