Preheat the oven to 350℉ and line a baking sheet with parchment paper or silicon mat.
In a mixing bowl, cream together softened butter, peanut butter, and brown sugar with an electric mixer until smooth, 2-3 minutes.
½ cup salted butter, ¾ cup peanut butter, 1 cup light brown sugar
Add in egg and vanilla and mix on medium speed until creamy and fluffy, about 1 minute.
1 large egg, 2 teaspoons vanilla extract
Add in flour, salt, and baking soda and mix until dough forms and no flour pockets are left, about 1 minute. Dough is going to be really soft and a little sticky! This is fine, don't be tempted to add more flour.
1½ cups all purpose flour , ¼ teaspoon salt, 1 teaspoon baking soda
Add in peanut butter chips, chocolate chips, and optionally chopped peanuts.
½ cup peanut butter chips, ½ cup chocolate chips, ½ cup chopped peanuts (optional)
Scoop onto baking sheet, flatten slightly (hockey puck shape) and bake for 8-10 minutes (don't overbake!!) until the edges are just beginning to crack.
Notes
Store at room temperature for 3-4 days, less for best results.