More Than Double

Name: More Than Double
Yield: Makes about 3 dozen.
Cuisine: Italian
Ingredients: 4 oz. semisweet or bittersweet chocolate, coarsely chopped; 1 tbsp. unsalted butter; 1 tsp. pure vanilla extract; 2 tsp. instant espresso powder; 1 tsp. salt; 2 cups granulated sugar; 1 large egg, lightly beaten; 12 oz. bittersweet chocolate, coarsely chopped; 4 large eggs, lightly beaten; ¼ tsp. instant espresso powder; 4 oz. unsweetened chocolate, coarsely chopped; 1 to 2 tsp. heavy (whipping) cream or half-and-half; 1 cup chopped walnuts or pecans, lightly toasted; ⅔ cup unsalted butter; 1 tsp. baking powder; 1¼ cups unbleached, all-purpose flour; ¾ cup firmly packed light brown sugar; ¼ cup + 2 tbsp. unsalted butter, softened to room temperature