In a medium bowl, whisk together flour, salt and baking soda. In a large bowl with either a hand or stand mixer, beat softened butter with peanut butter and both granulated and brown sugar until fluffy.
Add in eggs and vanilla extract and beat until smooth. Add the flour mixture into the wet ingredients in three separate additions. Beating after each addition until fully incorporated.
Cover and refrigerate for at least one hour. Preheat oven to 350 F. Roll cookie dough into balls and place onto large ungreased baking sheets. Bake for 10-12 minutes.
