Terry, New to TKL. I am still trying to figure out everything. I thought I'd work with the message board first. Saw your message and have a site for you to go to for all kinds of frosting recipes. Hope this helps. I also added a recipe for the specific frosting ou are looking for.
http://members.aol.com/Jimg004/frost2.html

* Exported from MasterCook II *

Chocolate Sour Cream Frosting

Recipe By : Ghirardelli Chocolate Company of San Francisco
Serving Size : 9 Preparation Time :0:00
Categories : Frostings

Amount Measure Ingredient -- Preparation Method
-------- ------------ --------------------------------
1/2 cup Sour cream
2 ounces Ghirardelli Unsweetened
3 1/2 cups Powdered sugar
melted
1 teaspoon Vanilla

Servings: Makes enough for 9 x 13" cake
DIRECTIONS: Beat sour cream with sugar and vanilla until smooth. Mix in melted chocolate. Spread over 9 by 13" cake.