I just made these cupcakes last night... I used the Pamela's Classic Vanilla cake mix and topped them off with a recipe I pulled from Epicurious.
I didn't realize how simple it is to make a ganache (or at least the recipe I pulled!). I got a food scale for Christmas so I'm starting to put recipes together this way... it's much more precise so I feel like I'm less likely to screw up.
to make the ganache you'll need:
12 oz of heavy cream
454 grams of chocolate (dark or semi-sweet, or really, whatever you like!)
1. in a heavy saucepan, bring the heavy cream to a boil.
2. once it boils, turn the burner off and add the chocolate to the mix and allow the chocolate to rest... it will start to melt pretty quickly.
3. use a rubber spatula to gently stir the mixture together until it gets smooth (keep the burner OFF!)
4. Once smooth, transfer to a room temperature bowl and cover with Saran wrap and put the bowl in the fridge to chill. Once it takes on the consistency of a a thick, thick peanut butter, spread on your cupcakes (or cakes... or face, whatever you like.)
I used Schokinag Chocolate Chunks for this... it's my favorite chocolate chip for baking just about anything.
This is the food scale I use: I love it! Just be sure to zero the scale once you put your bowl or whatever you are using the weight the foodstuffs...