Preheat the oven to 350 degrees. Coat three mini muffin tins with cooking spray.
Combine the softened butter, egg, brown sugar, peanut butter, white sugar, and vanilla extract together in a bowl. Mix with a beater until creamy and well combined.
Combine the flour, baking soda, and salt together in a bowl; mix well. Gradually add the flour mixture to the butter mixture until mixed. Add the chocolate chips and stir to combine. Scoop spoonfuls of the cookie dough to the mini muffin tin.
Place into the oven and bake for 10-13 minutes or until lightly golden brown. Remove from the oven and let them cool. Enjoy.