Line baking pans with parchment paper and set aside.
With an electric mixer, cream peanut butter and butter in a mixing bowl until smooth. Add brown sugar and beat until combined, scraping down bowl as needed. Add eggs and vanilla, and beat until incorporated.
In a small bowl, whisk together flour, baking powder, and salt. With mixer on low speed, gradually beat in flour mixture.
Roll spoonfuls of dough, a scant tablespoon in size each, between the palms of your hands. Then roll dough balls in a small bowl of sugar to coat completely. Place dough balls on prepared baking sheet, about 2" apart.
Bake for approximately 11 minutes, or until cookies are slightly puffed and just start to crackle on top. To achieve a moist, chewy center, do not over bake. Let cool on baking sheet for 5 minutes before transferring cookies to rack to cool completely.
Nutrition information is automatically calculated by Spoonacular. I am not a nutritionist and cannot guarantee accuracy. If your health depends on nutrition information, please calculate again with your own favorite calculator.