Have ready four 5- to 6-oz. ice pop molds and make room in the freezer, making sure the molds are level and secure.
Put 1/2 cup of the half-and-half, the chopped chocolate, and the sugar in a small heat-proof bowl and heat in a microwave or over simmering water until melted. Whisk until smooth with no gritty bits left undissolved. Reheat if necessary. Add the remaining half-and-half and the coffee liqueur and whisk until blended. To keep the chocolate mixture from separating during freezing, refrigerate, stirring occasionally, until it’s cold or, for faster chilling, set the bowl over a bowl filled with ice and stir frequently until cold.
Pour an equal amount of the chocolate mixture into the molds. Cover each mold with foil and push a wooden ice pop stick through the foil and into the middle of each pop. Freeze until firm, about 2 hours, or for up to 3 days.
To serve, remove the foil and slip the ice pops from the molds.
You can substitute rum or orange liqueur for the coffee liqueur, or for a non-alcoholic version substitute orange juice or an additional tablespoon of half-and-half.
Photo: Scott Phillips