Drain pineapple, reserving 1/2 cup juice. Beat cake mix, eggs, sour cream, oil and reserved pineapple juice in large bowl with mixer until blended.
Pour butter into 9-inch round pan; sprinkle with sugar. Arrange pineapple rings and cherries over sugar; sprinkle with 1/2 cup coconut. Cover with half the cake batter. Cover bottom of second 9-inch round pan with parchment; spray with cooking spray. Fill with remaining cake batter.
Bake 45 min. or until toothpick inserted in centers comes out clean. Cool cakes in pans 5 min.; invert onto wire racks. Remove pans and parchment; cool cakes completely.
Place plain cake on plate; spread with COOL WHIP. Sprinkle with remaining coconut. Top with second cake layer, fruit side up.