Using mixer on low to medium speed, mix peanut butter, oil, eggs, s/c milk and water until blended. Add in cake mix and continue mixing. Once well blended, using spatula, fold in peanut butter chips. (You can also use roughly chopped peanut butter cups or chocolate chips.)
Make 1” balls and roll lightly in sugar. Place on ungreased cookie sheet. If you want, slightly flatten with fork in crisscross pattern (I tend to do some this way and some not) or flatten a little with the palm of your hand.
Bake for 11-13 minutes or until golden brown and slightly cracked on top. Cool on the cookie sheet for a couple minutes to harden then move to rack to completely cool.