Preheat the oven to 350 degrees.
Lightly grease 1-2 cookie sheets, or line them with parchment paper and set them aside.
Add butter, peanut butter, granulated sugar and brown sugar in a large bowl and cream using a hand mixer or a stand mixer fitted with the paddle attachment. Mix for 1-2 minutes. Scrape down the bowl once complete.
Add the egg and mix until combined.
In a separate bowl, whisk together the dry ingredients (flour, baking soda, baking powder, salt).
Add dry ingredients to wet ingredients, about ½ cup at a time, mixing between each addition.
Roll dough into 1-inch balls and coat in additional sugar.