Preheat oven to 350 degrees. Grease 15X10X1 inch baking pan; set aside.
For crust: In medium bowl, combine 2 cups flour and brown sugar. Using pastry blender, cut in butter until mixture resembles coarse crumbs. Press mixture into bottom of prepared pan. Bake about 12 minutes or until golden.
Sprinkle peanuts and milk chocolate chips over crust. In small bowl, stir together caramel topping and 3 tablespoons flour. Drizzle over top.
Bake for 12 to 15 minutes or until caramel mixture is bubbly. Cool in pan on wire rack. Cut into bars.