Combine chocolate chips and margarine in a small saucepan; cook over medium low heat until chocolate melts, stirring constantly. remove from heat and stir in Kahlua and vanilla - set aside.
Beat brown sugar and egg in a large bowl until well blended. Add the chocolate mixture and beat well. then add the remaining dry ingredients. coat an 8 in square baking pan with spray and pour batter inches.
Bake at 350 for 30 minutes or until a toothpick comes out clean.
When they come out, immediately sprinkle sugar on top.