Preheat oven to 350 degrees. Grease 15 x 10 or 13 x 9 inch pan. In large bowl, beat brown sugar and shortening until light and fluffy. Add molasses, vanilla, and eggs; blend well. Lightly spoon flour into measuring cup; level off. Stir in oats, four, baking soda and salt; blend well. Stir in nuts and chocolate chips. Spread in prepared pan. Bake at 350 degrees for 20 to 25 minutes or until light golden brown and center is set. Cool slightly; cut into bars. Serve warm or cool. 48 bars.