Preheat oven to 350 degrees and grease a 9×13 pan. Set aside.
Mix cookie mix, oil, water and egg in a large bowl until combined and a soft dough forms. Press this mixture into the bottom of your greased pan.
Bake this for 12 – 14 minutes or until set. Remove from oven and immediately sprinkle on marshmallows and put back in oven for 1 – 2 minutes or until the marshmallows puff up.
In a large pot, add corn syrup, butter, vanilla and peanut butter chips and cook on low heat. Stir constantly until all combined and chips are melted.
Remove this mixture from the heat and stir in the Rice Krispies and nuts. Spoon mixture evenly over the marshmallows, trying to cover them all.
Let cool until set or refrigerate for 30 minutes before cutting into bars.