Preheat oven to 375°F.
In a large bowl using a handheld mixer, beat together the peanut butters, butter, granulated sugar, and brown sugar until fully combined.
Add the egg and vanilla. Mix to combine.
In a separate bowl, whisk together the flour, baking powder, and salt. Add to the wet ingredients and mix on low until just combined.
Using a 3-tablespoon cookie scoop, scoop the dough into balls. Roll each dough ball in granulated sugar. (OPTIONAL)
Place cookies 2 inches apart onto ungreased baking sheets.
Press each ball once with crisscrossing fork tines.
Bake for 8-10 minutes in the preheated oven, or until the edges are lightly browned. (Don't overbake these! They will get dry or crumbly quickly, so err on the side of less baking time.)