Everyone's favorite campfire treat and peanut butter come together in these REESE'S Peanut Butter Cup S'mores Bars. Picture layers of rich REESE'S Peanut Butter Cups and gooey marshmallow creme, sandwiched by golden brown graham cracker crust. No campfire required.
Heat convection oven to 300°F (standard oven: 350°F). Lightly spray two 13x18-inch half sheet pans with vegetable cooking spray. Place parchment paper on prepared sheet pans. Place pan extender on prepared sheet pans.
Mix butter and sugar in 20 qt. bowl of mixer fitted with paddle attachment until creamy. Add eggs, mixing until fully incorporated. Blend flour, graham cracker crumbs and baking powder in large bowl. Gradually add to butter mixture, mixing until well blended.
Press approximately 3 lbs. 6 oz. of dough onto EACH bottom of two prepared half sheet pans. Lightly press 44 REESE'S Peanut Butter Cups, cutting to fit as necessary, into the dough on EACH half sheet pan. Spread 1 lb. 5 oz. marshmallow creme, covering peanut butter cups, over EACH half sheet pans of peanut butter cups.
Divide remaining dough in half, forming each half into a ball. Place EACH ball on large sheet of waxed paper. With fingers, flatten and shape into 13x18-inch rectangle. Pick up waxed paper, supporting dough with hands. Flip dough onto marshmallow creme; press down lightly. Peel off waxed paper. Repeat for second ball.
Bake 20 to 30 minutes* or until edges just begin to brown. Cool completely in pan on wire rack. Cut into 3-inch squares.
Step 5: If using convection oven, rotate pans one-half turn (180°) after 12 minutes of baking