Blend sugar, oil, eggs, and vanilla in large bowl with wooden spoon.
Add flour, cinnamon, baking soda, and salt; mix well.
Fold in carrots, coconut, pineapple, and nuts.
Pour into well-greased 9X13 pan, or multiple layer pans, or spoon into foil cupcake liners. Bake about 35-50 minutes at 350°F. Cool 5 minutes in pan before removing onto wire rack(s) to cool completely.
When cakes are cool and ready to frost, beat cream cheese and butter together until smooth.
Add vanilla and powdered sugar; beat well.
Add milk, and continue beating until light and fluffy.
Frost with Cream Cheese Frosting. Decorate with additional chopped walnuts, if desired.