flower cupcakes

INGREDIENTS

• 18 tablespoons (2 1/4 sticks) unsalted butter, at room temperature
• 2 2/3 cups sugar
• 6 extra-large eggs, at room temperature
• 1 cup sour cream, at room temperature
• 1 1/2 teaspoons pure vanilla extract
• 3 cups all-purpose flour
• 1/3 cup cornstarch
• 1 teaspoon kosher salt
• 1 teaspoon baking soda
• 3/4 pound (3 sticks) unsalted butter, at room temperature
• 1 pound cream cheese, at room temperature
• 3/4 pound confectioners’ sugar, sifted
• 1 1/4 teaspoons pure vanilla extract