In a small bowl, stir together flour, baking powder, baking soda and salt; set aside. In a medium bowl, beat the 1/4 cup room-temperature butter with an electric mixer on medium to high speed for 30 seconds. Beat in granulated sugar, 1/2 teaspoon vanilla and 1/2 teaspoon almond extract. Add egg whites, one at a time, beating well. Alternately add flour mixture and buttermilk, beating on low speed after each addition just until combined. Spread half the batter in the pan. Chill remaining batter (or spread it in the second pan, if using).