My sister wants me to make one for her birthday. I would like a tried and tested recipe please she wants two layers I couldn't find a Rose Levy recipe. I will not have time to test the recipe

ACook's Illustrated has an excellent one.

This is my favorite.

http://www.bettycrocker.com/recipes/carrot-cake/64acd01e-14ad-4e03-9fe1-b62b03ff4667

Cake

1 1/2

cups granulated sugar

1

cup vegetable oil

3

eggs

2

cups Gold Medal™ all-purpose flour

2

teaspoons ground cinnamon

1

teaspoon baking soda

1

teaspoon vanilla

1/2

teaspoon salt

3

cups shredded carrots (5 medium)

1

cup coarsely chopped walnuts

The above recipe looks like my favorite traditional carrot cake. So good, especially with cream cheese frosting.  I also really like the recipe by Martha Stuart (link below) which is just a bit lighter and makes up nicely as a layer cake.  I also stir in  3/4 cup crushed well drained crushed pineapple  at the end (personal preference).  

http://www.marthastewart.com/344218/carrot-ginger-layer-cake-orange-cream-cheese-frosting#Carrot%20Cake%20Recipes|/274994/carrot-cake-recipes/@center/276954/great-cake-recipes|344218