Chocolate-Kahlua Brownies

1 1/2 cups granulated sugar
4 eggs
3 tablespoons Kahlua
1/4 cup margarine, melted
1 1/4 cups sifted cake flour
12 cup unsweetened cocoa powder
1 teaspoon baking powder
1/8 teaspoon salt
1/3 cup finely chopped walnuts

Heat oven to 325 degrees F. With an electric mixer, beat together sugar, eggs, Kahlua and margarine until blended. Combine cake flour, cocoa, baking powder and salt. Add to the sugar mixture, beating just to blend. Stir in walnuts.

Grease a 9-inch square baking pan. Transfer batter to the pan and bake for 30 minutes, until a wooden pick inserted in the center comes out clean. Cool completely on a rack before cutting.