The topping for the hi-hat cupcake is a little different than chocolate ganache, but it will give you a topping that gives a little crunch when you bite into it.  
We used the Seven Minute Vanilla Bean Icing Recipe or the swirl atop the cupcake and then chocolate dipped them. Also, TASTY!! The Ultimate Chocolate Butter Cake Recipe or UCBC used for the cupcakes.
CHOCOLATE RECIPE HELP

INGREDIENTS
12 ounces bittersweet or semisweet chocolate
3 tablespoons canola or flavorless vegetable oil

INSTRUCTIONS
1. Combine chocolate and oil in a medium heat-proof bowl (I use a stainless steel bowl) set over a medium saucepan of barely simmering water. Stir until melted and smooth.

2. Transfer to a narrow-ish bowl, and let cool about 15 minutes. Using a narrow bowl helps when you are dipping the cupcakes, because the topping will be deep.

3. Hold the cupcake by its bottom, and dip it into the chocolate to coat frosting. Allow excess to drip off, back into the bowl. -Spoon more coating around edge of cupcake and any exposed frosting. None of the frosting should show.

4. Place dipped cupcakes in the fridge, to allow topping to set.

STORAGE
You can store them in the fridge for a day, but they will not be quite as good if you store them longer than that.

The fluffy cross-section