Preparation

• Preheat oven to 375°F. Place grahams in food processor container; cover. Process until coarse crumbs form. Add margarine and peanut butter; cover. Process until well blended.
• Place graham mixture in 13x9-inch glass baking dish; press firmly onto bottom of dish to form crust. Sprinkle with chocolate chips; drizzle evenly with condensed milk, spreading gently to cover chips, if necessary. (Small holes will fill in as dessert bakes.)
• Bake 27 to 30 min. or until top is bubbly all over. Cool completely on wire rack. Before serving, sprinkle evenly with marshmallows. Broil, 3 to 4 inches from heat, 1 to 2 min. or until marshmallows are puffed and lightly browned. Let stand 1 min. before cutting into 24 bars to serve. Store in tightly covered container at room temperature.