Preheat oven to 350 degrees. Coat a 13 x 9 baking pan with non-stick spray. Pulverize cookies in a food processor or smash in a plastic bag until fine crumbs form. Add melted butter, process until the crumbs come together. Press into prepared pan and bake 15 minutes or until golden brown. Allow to cool slightly.

Melt 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 mix over the crumb base. Top with marshmallows and return the bars to the oven. Bake until the marshmallows puff, about 2 minutes, then remove from the oven. Don’t let the marshmallows brown or they’ll turn crunchy.

Toss the peanuts and cereal with the remaining peanut mixture to coat. Drop spoonfuls of the topping over the marshmallows, then spray a spatula with nonstick spray and use it to spread the topping. Cool the bars before cutting with a knife coated with non-stick spray.