Adapted from Martha
I make these with chocolate that contains 70% cocoa solids. If using a chocolate with 60% solids or less (or one that doesn't say) increase the flour to 1 cup (5 ounces).
My cayenne is on the elderly side (not sure how long it's been hanging around the spice cupboard) and the amount used here lends a warmth in the aftertaste, but not a tongue-scorching heat. (In fact, an unsuspecting five-year-old ate one at a party, and purportedly begged for another.) If your cayenne seems quite piquant, you might try decreasing the amount you use in the cookies.
If you like, you can press a chocolate chunk or two and/or some extra nibs into the tops of the unbaked cookies. I couldn't decide which I liked better, aesthetically.
Nutritional values are based on one of twenty four cookies.