PREHEAT oven to 350° F. Grease an 8-inch square baking pan.
COMBINE flour, oats, sugar, butter, baking soda and salt in a large mixing bowl until crumbly. Stir in 1/4 cup chopped peanuts. Reserve 3/4 cup crumb mixture. Press remaining crumb mixture onto bottom of prepared baking pan.
BAKE for 12 to 17 minutes or until lightly browned. Spread caramel topping evenly over hot crust. Sprinkle with ½ cup peanuts, marshmallows and morsels. Top with reserved crumb mixture.
BAKE for an additional 20 to 25 minutes or until topping is lightly browned. Refrigerate for at least 1 hour, or until firm. Cut into bars.