Put the chocolate, brown sugar, cinnamon, and cayenne in heat proof bowl in small pan over medium heat. Bring half and half to a simmer. Pour over the chocolate and whisk until chocolate is melted and mixture is well combined. Pour mixture into ice pop molds and insert sticks. Freeze until firm, at least 6 hours or up to 1 week. To unmold, run hot water over outsides of molds for a few seconds, then gently pull the ticks. Makes 6 to 8 pops.