Combine brown sugar, peanut butter, corn syrup and one tablespoon butter in a pan and bring to a boil on top of the stove over medium heat. Remove and add cereal and pecans.
Spray a 9 x 9 or 8 x 8 baking dish with cooking spray and press mixture into dish. Melt chocolate chips and the other tablespoon of butter in the microwave about one minute.
Spread over cereal mixture. Can add more chopped pecans on top. Store in refrigerator.
Notes
We take them out of the fridge and let them sit for about 10 minutes before cutting them into pieces.