Preheat oven to 350 degrees F. and grease a 9 inch square metal pan.
For the crust, combine 1 cup flour and ¼ cup brown sugar. Add butter and mix until well blended. Press into pan and bake for 15 minutes.
For the filling, beat eggs until thick and light in color. Gradually beat in ¾ cup brown sugar and continue beating until mixture is light and fluffy. Mix ¼ cup flour with the baking powder. Fold into egg mixture. Mix in coconut, vanilla and nuts. Spread over baked crust in pan. Bake 20 to 25 minutes longer or until lightly browned. Cool. Cut into bars.