PREHEAT oven to 350° F. Paper-line 24 muffin cups.
BLEND cake mix, water, oil and eggs in a large bowl at low speed until moistened (about 30 seconds). Beat at medium speed for 2 minutes. Spoon batter into prepared muffin cups, filling 2/3 full with batter. Sprinkle 1 cup morsels over batters in cups.
BAKE for 19 to 22 minutes or until wooden pick inserted in center comes out clean. Cool in pans on wire rack for 10 minutes; remove to wire racks to cool completely.
SPREAD cupcakes with frosting. Decorate with remaining morsels.