Preheat oven to 350.
Combine cake mix and butter completely mixed
Add eggs and beat until incorporated
Press mixture into the bottom of ungreased 13x9 baking pan.
Bake until it sets and the edges are lightly browned (about 15 minutes).
Remove from oven and immediately sprinkle marshmallows over hot crust.
Return the pan to the oven and bake for another few minutes until marshmallows puff up.
Remove from oven.
While the crust is baking, combine corn syrup, sugar and brown sugar in a saucepan (use one large enough to also hold the cereal and peanuts).
Bring to a boil over medium heat, stirring constantly.
Remove from heat and add in the peanut butter and vanilla and stir until smooth.
Stir in cereal and peanuts.
Spoon the mixture over the marshmallow topped base and spread to cover (use wax paper to help you cover the crust evenly).
Sprinkle candy corn over mixture evenly and gently press them in to the topping.
Let cool before cutting in the bars or squares