Cut chocolate into pieces; place in blender container or food processor bowl. Add sugar and cinnamon. Cover and blend or process until finely ground.
Cook and stir chocolate mixture and milk in a large saucepan over low heat about 10 minutes or until chocolate melts. Remove saucepan from heat; stir in vanilla and almond extract. Beat with a rotary beater until very frothy.
Serve in mugs. Top with whipped cream and chocolate shavings, if desired. Makes about 4 (8-ounce) servings.