Preheat the oven to 350°.
In a large mixing bowl, combine the sugar, oil, applesauce, eggs, and vanilla. Beat well.
1 1/2 c. sugar, 1/2 c. canola or vegetable oil, 1/2 c. applesauce (or you can substitute this with another 1/2 c. oil), 3 large eggs, 1 tsp. vanilla extract
Add the flour, salt, cinnamon, baking soda, and baking powder. Mix only to combine.
2 c. all-purpose flour, 1 tsp. salt, 1 1/2 tsp. cinnamon, 2 tsp. baking soda, 1/4 tsp. baking powder
Add the oats, nuts, shredded zucchini, and carrots. Stir to combine.
3/4 c. rolled oats (old-fashioned), 1 c. chopped walnuts or pecans, optional, 2 c. shredded zucchini, 1/2 c. shredded carrot (1 med. carrot)
Spread the batter onto a greased 10" x 15" jelly roll pan.
Bake at 350° for about 23 - 25 minutes or until a toothpick comes out with only a couple of crumbs.
Cool the bars then frost with the cream cheese frosting. Cut into bars and serve.
Store in the refrigerator for up to a week. Or you can also place the bars into an airtight container and freeze them for later.