Nun's Revenge Italian-Style Hot Chocolate

(Adapted from Fred Thompson's "Hot Chocolate: 50 Heavenly Cups of Comfort," Harvard Common Press, 2006.)

Think of this recipe as a double-dip dessert treat. Temperature plays an interesting role in this especially decadent sweetened hot chocolate. The addition of arrowroot powder -- a thickener that works something like cornstarch -- gives this treat a fuller-bodied consistency at higher temperatures and a light mousse-like texture as the mixture cools.

• 1 cup plus 4 tablespoons half-and-half
• 2 teaspoons arrowroot powder
• 2 tablespoon sugar
• 4 ounces bittersweet chocolate
• Strips of orange zest for garnish

In a small bowl, combine 2 tablespoons of the half-and-half with the arrowroot, whisking until smooth. Place the remaining cup of half-and-half in a small heavy-bottomed saucepan over medium heat. Bring to a simmer. When the half-and-half begins to bubble around the edges, whisk in the sugar. Whisk in the arrowroot mixture until the half-and-half thickens slightly, usually less than a minute. Remove from the heat and quickly whisk in the chocolate until smooth. Pour into espresso cups, top each with a piece of orange zest, and serve immediately.

Makes 4 espresso-sized portions.