2 c. whipping cream
2 c. half & half
2/3 c. sugar
1/3 c. unsweetened cocoa powder (preferably Dutch process)
2 1/2 oz. semi-sweet chocolate, coarsely chopped
6 eggs, beaten to blend
1/3 c. Jack Daniel's whiskey

Bring cream and half & half to simmer in heavy large saucepan. Add sugar and cocoa and stir until sugar dissolves. Remove from heat. Add chocolate and stir until smooth. Gradually whisk 1/2 cup chocolate mixture into eggs. Return to saucepan. Stir over medium-low heat until mixture thickens and leaves path on back of spoon when finger is drawn across, 10 to 15 minutes.

Strain into bowl set over larger bowl filled with ice. Cool completely, stirring often. Stir whiskey into custard. Transfer custard to ice cream maker and freeze according to manufacturer's directions. Freeze in covered containers several hours to mellow flavors. If ice cream is frozen solid, let soften in refrigerator before serving.