Cream together the butter, peanut butter, white and brown sugars with a hand or stationary mixer. Once creamy and smooth, mix in the egg and vanilla.
Sift the dry ingredients together and then combine them with the creamed ingredients.
Once the cookie dough is smooth stir in the chocolate chips.
Roll the dough into 1 1/2 inch balls and lay on a cookie sheet lined with parchment paper. With a fork, lightly press down to form cross mark on the cookies.
Bake at 350F for 12 minutes. Cool on a wire rack.