Make the cake:

1. Preheat oven to 350º.
2. Line inside of 9-inch springform pan with nonstick foil and wrap a piece of foil around outside, too.
3. Heat butter and chocolate in the microwave until melted. Whisk till smooth.
4. Whisk in the eggs and sugar.Add vanilla and pour into prepared pan.
5. Place the pan in a larger roasting pan and fill the larger pan with hot water to come about halfway up the sides of the pan.
6. Bake 40-45 minutes and remove from oven, allowing cake to cool in the water bath.
7. Once cool, place cake pan in freezer.

Make the mousse:

1. Melt butter and chocolate in the microwave. Whisk till smooth.
2. Whisk yolks, sugar and vanilla together.
3. Whisk yolk mixture into hot chocolate mixture carefully.
4. Using a mixer, beat the whites to stiff peaks. Fold the egg whites into the chocolate.
5. In the mixer, beat the cream to soft peaks and fold it into the mousse.
6. Spread mousse over the cold cake and return to freezer for an hour.

Make the Glaze:

1. Microwave corn syrup and cream just till hot. Add chocolate.
2. Let sit one minute and then whisk smooth. Let sit an additional 30 mins to thicken. Remove cake sides. Pour glaze over cold mousse layer and return to freezer for a few hours until ready to serve. Keep frozen. Let warm up at room temperature for a couple minutes before slicing and serving.