Grate the carrots into the medium bowl. Combine grated carrots and brown sugar. Set aside for 60 minutes (stir raisins if using)
Preheat oven to 350 degrees. Grease and flour two 10 inch cake pans.
In large bowl, beat eggs until light. Gradually beat in the white sugar, oil, and vanilla. Stir in the pineapple if using. Combine the flour, baking soda, salt and cinnamon, stir into the wet mixture add the walnuts if using. Finally stir in the carrot mixture and the walnuts. Pour evenly int the prepared pans.
Bake for 45 to 50 minutes in the preheated oven, until cake tests done with a toothpick come out clear. Cool for 10 minutes before removing from pan. When completely cooled, frost with cream cheese frosting.