Preheat oven to 350 and line two cookie sheets with parchment paper or silicone baking sheets.
In a medium mixing bowl, whisk together the flour, baking soda, baking powder and salt. Set aside.
Using a mixer, cream the softened butter and brown sugar for 3-4 minutes until light and fluffy. Add the peanut butter, eggs and vanilla and mix another minute., scraping down the sides of the bowl as needed.
Add the flour mixture and beat on low speed until just combined and no flour streaks, do not overmix.
Best if chilled for an hour or overnight. But if you can't wait, you can still bake these up, but they may spread a little if the dough is too warm. Feel free to add in chocolate chips, m&ms or anything else you want to at this time.
Using a medium cookie scoop, form the dough into balls and place them onto the baking sheets, allowing 2 inches between each cookie.
If you wish, you can slightly flatten each scoop of dough with the tines of a lightly-floured fork, creating a criss-cross pattern.
Optional, Sprinkle some sugar on top of the cookies then transfer to oven.
Bake for 8-10 minutes. The tops should look underdone, they will firm up as the cookies are cooling.
Remove the baking sheets from the oven and allow the cookies to rest for about 5 minutes before removing transferring to a cooling rack.