Preheat oven to 350°.
Coat 2 (9-inch) round cake pans with cooking spray; dust with 1 tablespoon flour.
Combine 2 1/4 cups flour, baking powder, and salt, stirring with a whisk. Place sugar and butter in a large bowl; beat with a mixer at medium speed until well blended (for about 5 minutes). Add eggs, 1 at a time, beating well after each addition. Add flour mixture and milk alternately to sugar mixture, beginning and ending with flour mixture. Stir in vanilla.
Pour batter into prepared pans. Sharply tap the pans once on countertop to remove air bubbles. Bake at 350° for 30 minutes or until a wooden pick inserted in the center comes out clean. Cool in pans 10 minutes on wire racks, and remove from pans. Cool completely on wire racks.
Place 1 cake layer on a plate; spread with 1 cup Fluffy Coconut Frosting. Sprinkle with 1/3 cup coconut. Top with remaining cake layer; spread remaining frosting over top and sides of cake. Sprinkle 1/3 cup coconut over top of cake. Store cake loosely covered in refrigerator.
(Totals include Fluffy Coconut Frosting.)