Make cake mix as directed on box, using water, oil and eggs. Use spatula to gently stir coconut and 1/2 cup chocolate sprinkles into batter. Divide batter evenly between pans. Bake as directed on box until toothpick inserted in center of each cake comes out clean. Cool cakes in pan 15 minutes. Transfer cakes to cooling racks. Cool completely, about 45 minutes.