Chocolate Nanaimo Bars

Base 3/4 cup butter 1/3 cup white sugar 1/2 cup dark cocoa 2 eggs, beaten 2 1/4 cups chocolate cookie crumbs 3/4 cup dessicated unsweetened coconut 1/2 cup chopped walnuts (optional) Filling 3 cups icing sugar 3 tbsps. Cocoa 1/3 cup butter, room temp. 1/3 cup cream...