1Heat oven to 400ºF. Mix brown sugar, butter and shortening in large bowl. Stir in 1 3/4 cups flour, the oats, salt and baking soda. Reserve 2 cups oat mixture; press remaining oat mixture in ungreased rectangular pan, 13x9x2 inches.
2Toss apples and 3 tablespoons flour; spread over mixture in pan. Heat caramels over low heat, stirring occasionally, until melted; pour evenly over apples. Sprinkle with reserved oat mixture; press lightly.
3Bake 25 to 30 minutes or until topping is golden brown and apples are tender. For 36 bars, cut into 6 rows by 6 rows while warm. Store covered in refrigerator.