Cut your sugar cone so it's about 2-3 inches long. Do this by pressing a knife to the cone at the cut line and rotating to score the full circumference. Then "saw" through to make a clean cut
Melt your white chocolate and dip the cone into it to completely cover. Add a bit of shortening to your chocolate if it looks too thick. Set on parchment paper, cut side down to cool. Place int he freezer 3-5 minutes to firm up.
Drizzle white chocolate on one side of the cone, immediately sprinkling liberally with gold sprinkles. Set on the parchment, unsprinkled side down. Do all 12 cones, and return to the freezer to set.
Repeat the sprinkle process on the other side of the cone.
To make unicorn frosting
Divide your frosting into 5 bowls (or however many colors you wish.)
Add 1 drop of food coloring to each bowl. I used pink, purple, blue, yellow, and white. Stir and decide if you need more color.
Add your piping bag to a tall cup and fold over the edges. I used an open star icing tip. Gently add frosting to each side of the bag, putting the white in the middle.
To assemble the Unicorn cupcakes
Pipe your frosting on your cupcakes. I used sprinkle cupcakes to go with the rainbow theme.
Gently add your horn to the center back of the cupcake.
Cut a mini marshmallow in half on the diagonal, and dip the cut side into pink sanding sugar.
Finally, put your marshmallow ears into the frosting, flat side down.
Gel coloring will make a more vibrant color. I used Wilton pink gel coloring. If you use normal red coloring, it will be a lighter pink.
I use a normal gallon sized zip top bag as my "pastry bag". Just snip the end and put your tip in the bag.
You also don't NEED a piping tip. Round would still be pretty!
If using store bought frosting, make sure it's room temperature and whip a bit to make sure it's not too thick.