Kahlua Brownies, Anyone?

Name: Kahlua Brownies, Anyone?
Yield: Makes about 3½ dozen.
Ingredients: 2 cups confectioners’ sugar, sifted; 1 tbsp. Kahlua; 4 large eggs, lightly beaten; 2½ tbsp. Kahlua, divided; 2 to 3 tsp. half-and-half or heavy (whipping) cream; 1 tsp. salt; 1 cup chopped walnuts or pecans, lightly toasted; 1 tsp. baking powder; 1 tsp. instant espresso powder; 2 cups granulated sugar; 1¼ cups unbleached, all-purpose flour; ⅔ cup unsalted butter; 4 oz. unsweetened chocolate, coarsely chopped; ½ cup unsalted butter, softened to room temperature