Preheat oven to 350 degrees. Line muffin tins with paper liners. In a mixer bowl, sift flour, sugar, baking soda, baking powder, and salt. Add eggs, yolk, water, buttermilk, vegetable oil, and vanilla; beat together.
Divide batter among liners, filling about 2/3 full. Bake until deep golden brown, about 30 minutes for large, 25 minutes for standard, and 22 minutes for mini. Transfer tins to rack to cool for about 15 minutes. Remove from tins; let cool completely.
To assemble: Divide buttercream in thirds (3 cups for bottom tiers, 2 for middle, and 1 for top); color each in a different pink. Using a dab of buttercream between layers as "glue," stack the cupcakes. Using a U-shaped petal tip (such as Ateco No. 80), pipe petals around outside of each layer, and continue inward.
Adorn your wedding cake with one of these thoughtful handmade touches.See the Ideas