Preheat oven to 350 degrees F.
Stir butter, eggs, and cake mix until combined.
Use greased hands to press cake batter into the bottom of a 13x9 inch baking pan.
Bake 15-17 minutes or until the edges are just barely golden brown.
Immediately cover with marshmallows. Return to oven for 2-3 minutes or until marshmallows puff up.
In a small sauce pan mix corn syrup, white sugar, and brown sugar.
Bring to a boil stirring CONSTANTLY!
Remove from heat and stir in peanut butter and vanilla. Fold in cereal and peanuts.
Spread over marshmallows. Sprinkle with candy corn.