Preheat oven to 400 degrees.
In a large mixer cream together butter, peanut butter, brown sugar and granulated sugar.
Mix on medium speed for 2 minutes.
Add in eggs and vanilla and mix until well blended.
In a medium bowl, whisk together salt, baking powder, baking soda and flour together.
Slowly add in flour mixture to the dough and mix it until just blended in.
Do not over mix.
Using a large cookie scoop or 1/4 cup measuring cup, scoop out dough evenly into balls.
Evenly space 6 cookie dough balls onto a standard baking sheet.
Using your hand or the flat bottom of a cup, gently press down the dough slightly.
Bake for 12-14 minutes until the edges are lightly golden brown and the center is just set.
*Do not over bake. They will continue to cook once you remove them from the oven.