Combine cake mix, ⅓ cup margarine and egg in a large bowl with a mixer on low speed until crumbly.
Press this mixture into the bottom of a greased 9" x 13" pan.
Bake at 350 degrees for 12-18 minutes or until golden brown.
Sprinkle the marshmallows over the crust mixture while still hot and then return it to the oven for 1-2 minutes or until the marshmallows just begin to puff.
Cool the crust mixture while preparing the topping.
In a large saucepan, heat the corn syrup, ¼ cup margarine, vanilla and peanut butter chips until the chips have just melted.
The mixture should be stirred constantly until it is smooth.
Remove the topping from the heat and stir in the cereal and nuts.
Immediately spoon the warm topping over the marshmallows and spread to cover.
Chill and cut into bars.
Recipe by Stephanie Bruntz Designs at http://stephaniebruntzdesigns.com/2017/03/salted-peanut-chews/