To prepare the filling, in a double boiler over simmering water melt the chocolate morsels. Remove pan from water. Add sour cream and stir until blended. Stir in rum or orange juice. Mix well. Let cool until chocolate mixture is thick enough to spread out.

Using a serrated knife, split the cake horizontally. Into 3 layers. Place bottom layer on a serving plate. Spread with half of the chocolate mixture. Top with the second layer of cake and spread remaining chocolate mixture. Top with third layer of cake.

Spread whipped topping over top and sides of cake. Chill for 1 hour before serving. Sprinkle with chocolate curls and garnish with raspberries.