Preheat oven to 350°.
Coat an 8-inch square baking pan with cooking spray, and dust with 2 teaspoons flour.
Place the butter in a large microwave-safe bowl. Cover and microwave at high for 1 minute or until butter melts. Add sugar, stirring with a whisk. Add vanilla and egg whites; stir well. Stir in the buttermilk, salt, and baking soda. Lightly spoon 1 1/2 cups flour into dry measuring cups; level with a knife. Add flour, stirring just until blended (do not overstir). Spread half of batter into prepared pan. Add cocoa and almond extract to remaining batter; stir well with a whisk. Slowly pour the chocolate batter over batter in pan.
Bake at 350° for 30 minutes or until a wooden pick inserted in center comes out clean. Cool for 10 minutes in pan on a wire rack. Cut into squares.