Inspired by the diamond birthstone, this all-white cake is pure elegance. Just like the diamond symbolizes strength, clarity, and timeless beauty, this cake features soft layers and delicate sweetness. Light and dreamy, it makes a sparkling centerpiece perfect for weddings, birthdays, or any special moment that deserves a touch of luxury and shine.
Heat oven to 350°F. Grease and flour two 6-inch round cake pans.
Prepare cake batter as directed on the package. Divide batter evenly between pans.
Bake 35 to 40 minutes, or until a toothpick inserted into the center comes out clean. Cool 10 minutes; remove from the pans and place on a cooling rack. Cool 30 minutes at room temperature. Place cake layers in the freezer for 20 to 30 minutes or until chilled but not completely frozen.
In a large bowl, beat softened butter with an electric mixer on medium-low speed for 2 to 3 minutes or until smooth and creamy. Add powdered sugar in batches, beating until smooth after each addition. Add vanilla, beat until well blended.
Using a serrated knife or a cake leveler, cut rounded tops off cake layers to create a level surface.
Spread a layer of the frosting on top of one of the cake layers; top with the second cake layer. Spread a thin coat of frosting over the entire cake to lock in the crumbs. Freeze for 10 minutes.
Frost the entire cake with an additional layer of frosting. Place remaining frosting in a piping bag fitted with a coupler.
Use an open star piping tip (such as #32) for the boarders around the top and bottom of cake and the rosettes where the scalloped ruffles meet the top border. Use a leaf piping tip (such as #112) to create the scalloped ruffles along the side of the cake.
