I am making carrot cake and pumpkin bars for Christmas tomorrow. I haven't yet tried either, but the frosting for them is AWESOME. It is from Better Homes and Gardens New Cookbook.
Cream Cheese Frosting
8-ounce package cream cheese, softened
1/2 cup butter, softened
2 teaspoons vanilla
5 1/2-6 cups powdered sugar
In a large mixing bowl beat cream cheese, butter and vanilla with an electric mixer on medium speed until light and fluffy. Gradually beat in powdered sugar to reach spreading consistency.
This frosts tops and sides of two 8- or 9-inch layers (This is why I ended up making carrot cake and pumpkin bars!). Halve this recipe to frost a 13x9x2 inch cake. Cover and store the frosted cake in the refrigerator.
Coco-Cream Cheese Frosting
Prepare as above, except beat 1/2 cup unsweetened cocoa powder into the cream cheese mixture and reduce powdered sugar to 5-5 1/2 cups.