Pre-heat oven to 350 degrees. Cream butter and peanut butter. Add cake mix, eggs, and salt. Add milk one tbsp at a time. Fold in peanut butter chips. Mix will be fudge-like. Use tablespoon to spoon out dough. Use hands to roll into a ball.Roll balls in sugar. Place onto un-greased cookies sheet. Use glass to press down balls into flatter shapes. Bake for 11-14 minutes until cookies start to crack. Remove from oven and allow to cool on the cookie sheet for 10 minutes. Enjoy!