Heat oven to 350°F. Grease bottom and sides of 13x9-inch pan with shortening or cooking spray. In large bowl, beat 2 cups flour, the oats, brown sugar, baking soda, salt and butter with electric mixer on low speed, or mix with spoon, until crumbly. Press about 3 cups of the mixture in pan. Bake 10 minutes.
Meanwhile, in small bowl, mix caramel topping and 3 tablespoons flour. Sprinkle apple and pecans over partially baked crust. Drizzle with caramel mixture. Sprinkle with remaining crust mixture.
Bake 20 to 25 minutes or until golden brown. Cool completely, about 1 hour 30 minutes. For bars, cut into 6 rows by 6 rows.