Preheat oven to 350 degrees F. Grease a baking sheet with butter and set aside. In a mixer combine peanut butter, chopped peanuts and sugars until well combined, about 2 minutes. Add eggs and baking soda and mix for another 2 minutes. Roll into walnut sized balls (1 tablespoon of dough) and flatten with your palm. If you’d like, add a few chocolate pieces to the top of the cookies. Bake for 10 minutes, until lightly browned. Cool on a baking sheet for two minutes, then transfer to a wire rack to cool completely.