1. Heat oven to 350 degrees . Grease and flour two 12-cup mini Bundt cupcake pans. Prepare cake mix according to package directions, using buttermilk in place of water. Spoon batter into prepared cupcake pans.
2. Bake at 350 degrees until toothpick inserted in center comes out clean, 15 to 20 minutes. Transfer to a wire rack and cool for 5 minutes. Invert and cool completely. Using a small serrated knife, trim domed tops to make them level.
3. Tint frosting orange with food coloring. Spread a little frosting on cut side of 12 of the cakes. Sandwich with remaining 12 cakes. Microwave remaining frosting for 5 to 10 seconds, until smooth but not too thin. Spoon some frosting on top of a stacked cake, allowing it to drip down the sides. Top with nonpareils or sprinkles. Cut a Tootsie Roll in half diagonally and reshape slightly with your hands. Add to top of cake as stem.
4. Repeat with other flavors of cake mix, if desired.