Make cake batter as directed on box. Pour into 2 mini muffin cups, filling two-thirds full. Pour remaining batter into round pans. Bake cupcakes 11 to 14 minutes, rounds 29 to 34 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes. Remove cakes from muffin cups and pans; place rounded sides up on cooling racks. Cool completely, about 1 hour. If necessary, cut off rounded tops of cakes.