Source: The Upper Crust Bakery - Austin, Texas
3 ounces unsweetened chocolate, chopped coarse
18 ounces semisweet chocolate, chopped coarse
1 stick (1/2 cup) plus 1 tablespoon unsalted butter, softened
3 large eggs
1 cup plus 2 tablespoons granulated sugar
1 tablespoon instant espresso powder
1 tablespoon vanilla extract
6 tablespoons sifted all-purpose flour
3/4 teaspoon salt
1/2 teaspoon baking powder
1 1/2 cups walnuts
1 1/2 cups pecans
Preheat oven to 325 degrees F.
In a double boiler or a metal bowl set over a pan of barely simmering water melt unsweetened chocolate, 9 ounces semisweet chocolate, and butter, stirring occasionally, and remove top of double boiler or bowl from heat.
In a bowl with an electric mixer beat eggs with sugar until light and fluffy. Add espresso powder, vanilla extract and chocolate mixture, beating until smooth.
In a small bowl whisk together flour, baking powder, and salt and add to chocolate mixture, beating until just combined. Stir in remaining semisweet chocolate and nuts until combined well.
Scoop out 1/2-cup measures of cookie dough, arranging them 3 inches apart on ungreased baking sheets. Bake cookies in batches in middle of oven 25 minutes, or until tops begin to crack (do not overbake). Cool cookies on a rack.
Yields 12 (3- to 4-inch) cookies.