Preheat oven to 350℉ and line two baking sheets with parchment paper.Combine the flour, baking soda and salt in a medium bowl. Set aside.Beat together the butter, peanut butter, brown sugar, and granulated sugar until light and fluffy. Using a stand mixer really makes a difference, but a hand mixer will work as well. To the butter and sugars add in the egg and vanilla and mix until well combined. Using low speed, gradually add in the flour mixture. Stir until dough forms and no white streaks are seen. Using a medium cookie scoop (about 1 heaping tablespoon of dough), drop rounded balls of dough onto prepared baking sheet, 2 inches apart. If you would like the extra sparkle and classic look, sprinkle with a little sugar on each cookie if desired. Bake for 10 to 12 minutes. Just until edges are slightly golden and set. 10 minutes is perfect for me every time. Cool for 5 minutes on cookie sheets before transferring cookies to a wire rack to cool completely. *no need for criss cross like regular peanut butter cookies.