Again, I made the mistake of using semisweet chocolate chips melted with shortening to coat these. They didn't harden well, much like the Peanut Butter Patties (note the finger prints on the picture below). I plan on making these again for Christmas and when I do, I'll use candy coating. Wilton even makes a chocolate mint flavored coating eliminating the need for the peppermint extract.
I've written the recipe out below using the measurements that I've found to be the same throughout the many different versions I've found across the net. I used the same amount of peppermint listed below for 12-oz of semisweet chocolate and I didn't find it minty enough. Most likely, it'll depend on your palate. My suggestion is to add the 1/2 tsp then taste the chocolate before dipping.