Cream butter or margarine with brown sugar and white sugar. Add egg and vanilla. Mix well. Stir in peanut butter, baking soda, and salt. Make sure it is well blended. Add flour and chocolate chips.
Drop teaspoons of cookie dough then flatten with fork slightly on greased cookie sheet. Bake for 5-6 minutes or until just showing a hint of brown on edges. Don't overcook. Let cool on cookie sheet for 5 -10 minutes. Then transfer to cooling rack.