Preheat oven to 350°. Grease 13×9-inch pan. Lightly spoon flour into measuring cup and level off. Combine all crust ingredients until crumbly. Press half into bottom of prepared pan. Reserve remaining mixture for topping. Bake at 350° 10 minutes.
Filling: Sprinkle warm base with chocolate chips and nuts. Combine caramel topping and 3 tablespoons flour. Drizzle evenly over chocolate chips and nuts. Sprinkle with reserved crumb mixture. Bake an additional 18 to 22 minutes or until golden brown. Cool completely. Cut into bars.