Preheat oven to 350 degrees F.
Grease a 9 inch square metal pan or line with foil and grease.
Mix the flour with baking powder and salt.
Melt butter with chocolate (can use microwave or a saucepan).
With an electric mixer, beat eggs with sugar until light. Add chocolate mixture and kahlua, then sir in flour mixture and nuts. Blend well.
Pour into prepared pan and bake 30 to 35 minutes or until the top springs back in the center and edges begin to pull away from the pan.
Remove from oven and cool thoroughly in pan. Brush top with 1 T Kahlua.
When cool, lift from pan and cut into 16 thick brownies.