In a large bowl of an electric mixer, beat butter until light and fluffy, about 3 minutes. Add both sugars and mix until no granules remain, about 5 minutes. Add peanut butter and mix until combined. Add eggs; continue to beat on high speed for 1 minute.
In a large bowl, combine flour, baking soda and salt. Slowly add flour mixture to butter mixture; stir until well-blended.
Drop dough by heaping TBL onto greased baking sheets. Flatten dough with palm of hand to form 3" circles that are 1/4" thick.
Bake cookies for 10-12 minutes or until lightly browned on the bottom.
Nutrition facts per cookie: 105 calories, 7 g fat, 3 g saturated fat, 17 mg cholesterol, 10 g carbohydrates, 2 g protein, 25 mg sodium, 0 g fiber