Place chopped chocolate, in a medium heatproof bowl. In a small pan over medium heat, bring heavy cream just to a simmer. Pour the cream over the chocolate; let stand 1 minute. Stir liqueur, instant-espresso powder, ground cinnamon and cayenne into the warm ganache until smooth; chill until firm, about 2 hours. Form into balls using a 1/2-inch ice cream scoop or a tablespoon measure, and roll in unsweetened cocoa powder. Pinch the tops twice, at 90-degree angles, to form pyramid shapes; chill until firm, about 30 minutes.
The Do's and Don'ts of Cooking with Chocolate