Beat butter at medium speed with an electric mixer until creamy; gradually add 2 cups sugar, beating well. Add eggs, 1 at a time, beating until blended after each addition.
Combine flour, baking powder, and salt; add to butter mixture alternately with milk, beginning and ending with flour mixture. Beat at low speed until blended after each addition. Stir in flavorings. Pour batter into 3 greased and floured 9" round cakepans.
Bake at 350° for 18 to 20 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes; remove from pans, and cool on wire racks.
Combine 2 tablespoons sugar and coconut milk in a small glass bowl. Microwave on HIGH 1 minute; stir until sugar dissolves. Brush 1 cake layer with half of coconut milk mixture, leaving a 1/2" margin around edges. Spread with 1 cup Boiled Frosting, and sprinkle with 1/2 cup shredded coconut. Top with second cake layer, and repeat procedure. Top with remaining cake layer. Spread remaining frosting on top and sides of cake; sprinkle with remaining coconut. Garnish, if desired.