Heat oven to 325. Mix butter, confectioner sugar and 2 cups flour. Press into bottom of a 10 x 15-inch pan. Bake 10 to 15 minutes or until light brown. Beat eggs with sugar. Add 3 tablespoons flour, baking powder, lemon juice and salt. Stir in coconut. Pour over crust. Bake 25 minutes or until set and light brown. Cool. Cut into 2-inch squares or into fingers. Dust with confectioner sugar.