Heat oven to 350°F. Grease 13 x 9-inch metal baking pan. For crust, beat flour, sugar, butter, baking soda and salt in large bowl with electric mixer until crumbly. Beat in oats on low speed just until combined. Press half of mixture (about 2-1/2 cups) into bottom of baking pan. Bake 10 minutes. Cool in pan for 2 minutes. For filling, sprinkle chips and nuts over crust. Blend caramel topping with flour. Drizzle over morsels and nuts. Crumble remaining oat mixture over nuts. Bake 18 to 22 minutes or until golden brown. Cool completely in pan on wire rack. Cut into bars.