1) Preheat the oven to 350°F. Grease an 8" x 2" square pan or a 9" x 2" round pan.
2) To make the cake: Stir together the dry ingredients; set aside.
3) Whisk together the melted butter or oil, eggs, water, molasses, and vanilla.
4) Stir the dry mix into the wet ingredients. Scrape the bottom and sides of the bowl and continue to stir for about 30 seconds, until well blended.
5) Fold in the grated carrots, fruit, and nuts.
6) Transfer the batter to the pan, smoothing the top with a spatula. Allow the batter to rest for 10 minutes before baking.
7) Bake the cake for 35 to 45 minutes, until a cake tester inserted into the center comes out clean.
8) Remove the cake from the oven. Allow the cake to rest for 5 minutes before turning out of the pan onto a rack to cool completely before frosting. Alternatively, you can frost and serve the cake right from the pan.
9) To make the frosting: Beat the butter and cream cheese until smooth.
10) Add the salt and vanilla, then beat in the sugar.
11) Beat in an additional teaspoon of milk or cream if the frosting is too stiff to spread; beat in more sugar if it's too thin.
12) Spread the frosting over the cake.
Yield: one 8" square or 9" round cake.