Lemon Meringue Butter Cake

Name: Lemon Meringue Butter Cake
Ingredients: 2 large egg whites; ½ cup granulated sugar; ¼ teaspoon cream of tartar; ¼ cup unsalted butter (½ stick) (at room temperature); 1 teaspoon finely grated lemon zest (from 1 lemon); 1 large egg (at room temperature); ½ cup full fat sour cream (at room temperature); ½ teaspoon baking soda; 1 cup all-purpose flour; ¾ teaspoons baking powder; ½ teaspoon fine sea salt; 2 tablespoons Amoretti Natural Lemon Meringue Artisan flavor; 1 tablespoon freshly squeezed lemon juice; 1/2 teaspoon vanilla extract