Vanilla Purple Cake with Lemon Buttercream

Ingredients

• Vanilla Purple Cake:
• 3 sticks unsalted butter, at room temperature, plus more for the pans
• 4½ cups all-purpose flour, plus more for the pans
• 1½ tablespoon baking powder
• 1 teaspoon salt
• 2½ cups sugar
• 6 large eggs, at room temperature
• 2 vanilla beans, seeds only
• 1½ cup heavy cream
• 15 drops purple food gel color, you can use more or less, depending in the color you want to achieve
• Lemon Buttercream:
• ½ cup butter, softened
• 4½ cups confectioners' sugar
• 1 tablespoon lemon zest
• 6 tablespoons fresh lemon juice
• 1 vanilla bean, seeds only
• pint of fresh blackberries