Combine first five ingredients and set aside. Melt butter in saucepan, add brown sugar, mix well. Cool slightly. Add beaten egg and vanilla, blend. Add flour mixture slowly, beating with each addition. Spread in greased 9x9 inch pan. Sprinkle chocolate bits on top. Bake at 180ºC or 20 to 25 minutes. Do not overcook. Cool in pan. Cut into bars. Enjoy, Janis.