Preheat oven to 325 °. Cream together sugar, eggs and oil. Mix dry ingredients and add to the wet ingredients. Then add carrots and vanilla. Pour into 2 greased and floured round cake pans. (I’ve started using that baking spray with the flour already in it. It seems to work like a charm!)
Bake for about 45 minutes, testing with a toothpick until it comes out clean. Cool the layers completely before making the icing.
Mix together the cream cheese and butter until fluffy. Add the powdered sugar. Mix until you have a smooth frosting. Add the optional pecans, or use them to decorate the cake.