Prep: 20 min., Bake: 52 min., Cook: 25 sec., Cool: 1 hr. Be sure to sprinkle the peanut topping around the edges of the pan to seal in the jelly mixture.
Preheat oven to 350° . Line bottom and sides of a 13- x 9-inch pan with heavy-duty aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease foil.
Cut 1 cup butter into small pieces. Pulse butter pieces, all-purpose flour, and powdered sugar in a food processor 5 to 6 times or until mixture is crumbly. Press mixture into bottom of prepared pan.
Bake at 350° on an oven rack one-third up from bottom of oven 22 to 24 minutes or just until golden brown.
Meanwhile, whisk together jelly, peanut butter, and 1/4 cup peanut flour in a small bowl until smooth.
Microwave remaining 1/4 cup butter in a microwave-safe bowl at HIGH 25 seconds or until melted. Stir in peanuts, next 4 ingredients, and remaining 1/2 cup peanut flour until well blended and crumbly.
Spread jelly mixture over crust, leaving a 1/2-inch border. Sprinkle peanut mixture around edges of pan and over jelly mixture.
Bake at 350° for 30 minutes or just until jelly mixture begins to puff. Cool completely in pan on a wire rack (about 1 hour).
Carefully and quickly lift baked bars from pan, using foil sides as handles. Place on a cutting board, and cut into 24 bars.
Note: We tested with 12% fat light roast peanut flour.