Preheat oven to 350°F (I have found that if you lower the oven temperature to 325, it will often prevent the "doming" of the layers.

Grease and flour 2 8-inch pans OR butter and line with parchment paper.

In a large mixing bowl, cream together the butter, shortening, baking powder, sugar, salt and extracts until light and fluffy, about 6 minutes.

Add the egg whties to the butter mixture one at a time, beating well after each addition.

Stir 1/3 of the flour into the creamed mixture, then half the milk.

Repeat process, ending with flour.

Be sure to scrape the sides of the bowl down after each addition.

Pour the batter into the prepared pans.

Bake for about 23 minutes, or until cake tests done.

Cool completely in pans on wire racks.