Recipe for Chocolate Mousse Torte?

Does anyone know the recipe for a dessert called Chocolate Mousse Torte? I had it a few times at some restaurant near Berkeley, CA circa 1980. It was very dense and was served in a wedge like pie. This is the best chocolate dessert I have ever had. The people at the restaurant said they did not make the dessert, but bought it from some nearby bakery which they would not disclose. Any ideas?

Thanks for the recipes. The first one looks like it might be close to what I had. If my memory still serves, it was more like a creamy cheesecake rather than a fluffy mousse. I see how it turns out.