With a hand mixer, cream together the peanut butter, butter, white sugar and brown sugar until blended.
Beat in the egg, milk, and vanilla.
Combine the flour, baking powder and salt in a separate bowl.
Add flour mixture to the peanut butter mixture and mix together. Stir in chocolate chips at this point if desired.
Scoop tablespoonfuls of dough and roll into balls.
Place cookies 2 inches apart on ungreased cookie sheets (I used parchment paper since my cookies tend to burn on my darker pans). Press each ball once with a fork.
Bake for 8-10 minutes at 375. Don’t overcook! These cookies are much better soft and just barely cooked all the way through! Enjoy!