Spray a 9x13in baking dish with non-stick cooking spray.
In a small pan, mix brown sugar and honey. Heat and stir until boiling, then boil for at least 2-5 minutes, taking care to not burn. Remove from heat and stir in peanut butter. Pour in measured cereal and oats; mix well.
Press firmly a into prepared baking dish. Allow to cool and cut into 10 bars. As they rest, bars will become semi-crunchy.