1Heat oven to 350°F (or 325°F for dark or nonstick pans). Place paper baking cup in each of 18 regular-size muffin cups; place mini paper baking cup in each of 18 mini muffin cups. Make cake batter as directed on box. Spoon batter evenly into regular and mini muffin cups.
2Bake mini cupcakes 10 to 14 minutes, regular cupcakes 15 to 20 minutes (18 to 24 minutes for dark or nonstick pan), or until toothpick inserted in center comes out clean. Remove from pans to cooling racks. Cool completely, about 30 minutes.
3If ice cream cone holder is unavailable, make a holder for the cones by tightly covering the tops of 2 empty square or rectangular pans (at least 2 to 2 1/2 inches deep) with heavy-duty foil. With sharp knife, cut 18 "stars" in foil, 3 inches apart, by making slits about 1 inch long.
4Place about 2 teaspoons candies in each ice cream cone. Remove paper cups from cupcakes. For each cone, frost top of 1 regular cupcake with frosting; turn upside down onto a cone. Frost bottom (now the top) of cupcake. Place mini cupcake upside down on frosted regular cupcake; frost side of regular cupcake and entire mini cupcakes completely (it's easiest to frost from the cone toward the top). Sprinkle with candy decors. Push cone through foil opening in cone holder; the foil will keep it upright. Store loosely covered.