Tear up the cake into small pieces. Place half of the cake pieces in a 9 x 13 inch baking pan. Beat the eggs until they are thick and lemon colored. Set aside.
In a pan over simmering hot water or double boiler, melt the chocolate. Cool a little. Add a bit of the chocolate to the eggs to temper and then add the egg mixture to the chocolate. Stir. Be careful to not let the eggs cook and become scrambled eggs.
Fold the chocolate mixture into the whipped topping (or whipped cream), the vanilla and 3/4 cup or nuts. Pour half of the mixture over the cake pieces in the pan, top with remaining cake pieces and then the remaining chocolate mixture. Sprinkle rest of the nuts over the top. Cover with saran wrap and refrigerate for approximately 12 hours. Serve with whipped cream.
Can use milk chocolate instead of semi-sweet chocolate bits.