Mix flour, sugar, soda, salt, and cinnamon. Then add vegetable oil, grated carrots, eggs, and chopped pecans. Mix well.
Bake at 350°F in 3 greased 8" pans for 40-45 min. Allow to cool completely.
Mix the cream cheese frosting and spread some between the cake layers while assembling the cakes one on top of each other. Now spread the rest of the frosting on the outside (starting on top first, then the sides - using a spatula). Carefully apply by hand the chopped pecan for the sides.