Instructions

• Preheat oven to 350°F (175°C). Line an 8x8-inch baking pan with aluminum foil, leaving some foil overhang to lift the bars out later, and spray the foil with cooking spray; set pan aside.
• Make the crust: in a large bowl combine 1 cup all-purpose flour and 1/4 cup confectioners’ sugar. Add 1/4 cup creamy peanut butter and 1/2 cup unsalted butter (softened).
• Cut the butter into the dry ingredients and peanut butter using two forks, a pastry cutter, or your fingertips until the mixture forms pea-sized crumbs and is evenly combined.
• Turn the crust mixture into the prepared pan and press it down firmly and evenly with your fingertips or the bottom of a measuring cup to form a smooth, compact layer.
• Bake the crust for 15 to 17 minutes, or until the crust is set (do not overbake or brown it). Remove the pan from the oven.
• Immediately and evenly sprinkle about 2 heaping cups marshmallows (most of one 10-ounce bag; use large marshmallows for thicker bars or mini marshmallows for thinner bars) over the hot crust.
• Return the pan to the oven and bake 2 to 4 minutes, watching closely after 2 minutes, until the marshmallows have puffed but are not browned. Remove the pan from the oven as soon as marshmallows are puffed.
• While the marshmallows are puffing, prepare the topping: in a large microwave-safe bowl combine one 10-ounce bag peanut butter chips, 1/3 cup light-colored corn syrup (not “lite”), and 2 tablespoons unsalted butter.
• Microwave the peanut butter chip mixture on high in 30-second intervals, stirring between intervals, until the mixture is fully melted and smooth (about 1.5–2 minutes total, depending on your microwave). Be careful not to overheat.
• Stir 2 teaspoons vanilla extract into the melted mixture until combined.
• Add 1 1/2 cups Rice Krispies (or similar crispy rice cereal) and 1 1/2 cups salted peanuts (or salted honey roasted peanuts) to the melted mixture and stir until the cereal and peanuts are evenly coated.
• Pour and spread the peanut-chip/cereal/peanut mixture over the puffed marshmallows in the pan, smoothing the top with a spatula and pressing down lightly so the layers adhere.
• Cover the pan with foil and refrigerate for at least 2 hours, or until the bars are fully set.
• Use the foil overhang to lift the set slab from the pan. Transfer to a cutting surface and slice into bars. Store bars airtight at room temperature for up to 5 days or freeze for up to 6 months.