- 6 cups strong hot espresso (about 36 ounces)
- 1 to 1 1/2 cups sugar, plus 2 tablespoons for the whipped cream
- 4 tablespoons unsweetened Dutch process cocoa powder
- 2 cups half-and-half or milk
- 6 to 8 cups crushed ice
- 1 cup very cold heavy cream
- 1 teaspoon vanilla extract
- 6 ounces bittersweet chocolate, finely grated
Place the hot espresso in a medium bowl and sweeten with sugar to taste. Whisk in the cocoa powder until smooth. Add the half-and-half or milk, combine well, and refrigerate until cool, about 1 hour.
Place one-fourth of the espresso mixture and one-fourth of the ice in a blender and blend until smooth and thick, adding more ice if necessary. Remove to a bowl and place in the freezer to keep cool. Repeat in batches with the remaining mixture, and add to the mixture in the bowl.
Place the heavy cream, 2 tablespoons of sugar, and vanilla extract in a medium bowl and beat to soft peaks with a hand-held mixer.
Spoon espresso-chocolate mixture into 8 glass Irish coffee mugs and top with whipped cream and shaved chocolate. Serve with spoons and straws.