Preheat the oven to 350F degrees and spray a 9-inch springform pan with nonstick cooking spray.
In a bowl, whisk together the flour, baking powder, and salt; set aside. In the bowl of a stand mixer fitted with the whisk attachment, whip the egg whites on high until soft peaks form. Add 1/4 cup of granulated sugar, and continue whipping until stiff and glossy peaks form. Transfer whites to another bowl.
Return bowl to the mixer, add the egg yolks and remaining 3/4 cup granulated sugar. Beat on high until thick and pale yellow. Stir in the milk, vanilla, and optional almond extract. Remove bowl from mixer and fold in the flour mixture until just combined—do not overmix. Gently fold in the egg whites, then pour batter into prepared pan. Bake for 30-32 minutes, or until a toothpick inserted in the center comes out clean. Allow cake to cool completely.