Steps

1. Preheat oven to 350°F and adjust rack to center of oven. Butter and flour two 9x2-inch cake pans.
2. In the bowl of an electric mixer, beat the eggs until smooth. Add the sugar and brown sugar and beat on medium-high speed until fluffy and thick, about five minutes. Reduce speed to medium and add the oil in a slow, steady steam. Turn speed to high and beat for another minute.
3. In a large bowl, sift together the flour, baking powder, baking soda, cinnamon and salt. Fold 1/3 of the flour mixture at a time into the egg-sugar-oil mixture, then stir in the carrots, walnuts and raisins.
4. Divide the batter between the two cake pans and bake for 40-45 minutes, until a toothpick inserted in the center of the cake comes out clean. Remove the cakes to a wire rack and cool completely in their pans.
5. In a mixer fitted with the paddle attachment, beat together the cream cheese and butter until light and fluffy. Scrape down the sides of the bowl to mix evenly. Add the powdered sugar, vanilla and salt and beat on low speed until incorporated. Increase speed to medium and blend one minute more.
6. Remove one cake layer to a 10-inch cake circle or service tray. Spread evenly with a 1/3-inch thick layer of cream cheese frosting on top. Invert the other cake layer and place it on top bottom layer. Spread a thin layer of frosting around the sides to seal the cake and prevent crumbs from showing through the final layer of frosting. Frost the top in the same manner. Chill the cake for ten minutes to set the icing.
7. Cover the entire cake with a final one-third inch layer of frosting. Use any remaining frosting to apply decorative border decorations.  Store covered and refrigerated. Allow to warm to room temperature about an hour before serving.

Notes

Carrot cake has been around in the United States since at least the 1960s, but its popularity really took off in the 1970s.