PREHEAT oven to 350° F. Grease or paper-line 24 muffin cups.
COMBINE cake mix, water, vegetable oil and eggs in large mixer bowl. Beat on low speed for 1 minute; scrape down side of bowl with rubber spatula. Beat on high speed for 1 minute. Stir in 1 1/2 cups morsels. Spoon batter into prepared cups, filling 2/3 full.
BAKE for 15 to 20 minutes or until wooden pick inserted in cupcake comes out clean. Cool in pans on wire racks for 10 minutes. Remove to wire racks to cool completely.
FROST cupcakes. Sprinkle with remaining 1/2 cup morsels.