Pre-heat oven to 350 degrees. Pour melted butter into a 9x13 baking pan. Sprinkle 1 1/4 cups graham cracker crumbs over the melted butter. Pat down gently. Then scatter milk chocolate chips, the white chocolate chips, chopped peanut butter cup, mini marshmallows, and 1/2 cup graham crackers crumbs. Next, pour entire can of sweetened condensed milk evenly on top. Bake for 15-20 minutes or until marshmallows are golden brown on top. Let cool completely before cutting.