Sponge Cake: 1 cup flour 2/3 cup sugar 1 teaspoon zest of lemon 5 large eggs, room temperature Lemon Curd: 6 large egg yolks 1 cup sugar 3/4 cup lemon juice pinch salt zest of 1 lemon 2 tablespoons unsalted butter Meringue: 1 cup egg whites 2 cups sugar...