Preparation Steps

• Preheat oven to 350°F (175°C). Line a 9-inch square baking pan with foil, leaving an overhang on all sides for easy removal. Grease the foil well.
• In a large bowl, cream together the softened butter and brown and granulated sugars until light and fluffy, about 3 minutes.
• Beat in the egg and vanilla extract until well combined.
• In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Stir in the crushed graham cracker crumbs.
• Press two-thirds of the dough evenly into the bottom of the prepared baking pan.
• Spread the peanut butter evenly over the dough layer. Sprinkle the chocolate chips over the peanut butter, then carefully spread the Marshmallow Fluff over the chocolate chips.
• Gently press the remaining one-third of the dough evenly over the Marshmallow Fluff layer.
• Bake for 25-30 minutes, or until the edges of the crust are golden brown. The center may appear slightly soft.
• Remove the pan from the oven and let it cool completely on a wire rack for at least 1 hour. This allows the bars to set.
• Once cooled, use the foil overhang to lift the entire block out of the pan. For easier cutting, chill the bars in the refrigerator for another hour. Use a sharp knife to cut into 16 bars, cleaning the knife between cuts if necessary.