Place oven rack in the center position and pre-heat oven to 375°F. Line two large baking sheets with parchment paper or a Silpat® baking mat and set aside.
Mix the butter, peanut butter, brown sugar, and granulated sugar in a large mixing bowls. Add the eggs and vanilla extract, and mix to combine.
1 cup unsalted butter, 1 1/2 cups light brown sugar, 1/2 cup granulated sugar, 2 large eggs, 2 tsp. vanilla extract
In a separate large bowl, combine the flour, baking soda, baking powder, and 2/3 cup unsalted peanuts. Slowly add the dry ingredients to the wet ingredients and mix until just combined.
2 1/2 cups all-purpose flour, 1 1/2 tsp baking soda, 1 tsp baking powder
Transfer dough to the refrigerator and chill for one hour.
Once chilled, divide the dough into equal-sized balls and arrange on the prepared baking sheets, leaving 2 inches between each ball. Press the dough down with a fork in a crisscross fashion to flatten. Add remaining chopped peanuts to the top of the cookies and press the peanuts down into them.
1 1/2 cups chunky peanut butter, 1 cup unsalted peanuts
Place the baking sheets into the pre-heated oven and bake for 10-12 minutes, or until the cookies are golden brown on top and cooked through.
Remove from the oven and let the cookies sit for 2-3 minutes before transferring to a wire rack to cool before serving. Enjoy!