• Preheat oven to 350 degrees F and line a 9x13 baking pan with parchment paper sprayed with non-stick cooking spray.

For crust:

• Pulverize cookies in a food processor until fine crumbs form. Add melted butter and process until crumbs clump together.
• Press crumbs into the bottom of the prepared 9x13 pan. Bake for 15 minutes or until golden.

For topping:

• Melt the peanut butter chips, corn syrup, butter, and vanilla in a saucepan over medium-low heat, stirring until smooth, about 5 minutes.
• Spread 1/2 cup of the peanut mixture over the cooked crumb base.
• Top with marshmallows and return the pan to the oven. Bake until marshmallows puff up, about 2 minutes, then remove from oven. DO NOT let the marshmallows brown or they will turn crunchy.
• Add peanuts and cereal to the remaining melted peanut butter chip mixture and stir to evenly coat.
• Drop spoonfuls of the peanut topping over the marshmallows and carefully spread with a non-stick silicone spatula. If the mixture is still sticking to the spatula, spray the spatula with non-stick cooking spray. Continue until evenly coated.
• Let the bars fully cool before cutting.