Spray the bottom and sides of a 8 or 9 inch springform pan. Wrap in two layers of aluminum foil and set inside a 9x13 or larger baking pan, tall enough for you to add water to come halfway up the sides of the springform pan. Don't add water yet.
Reserve 1/2 cup of semisweet chocolate chips and set aside. Place remaining chips and butter in double boiler OR microwave safe bowl and heat over hot water or in microwave until chips melt, stirring frequently. If you use the microwave, stir every 30-45 seconds to keep chocolate from scorching.
Stir in vanilla.
In medium bowl, beat eggs. Place bowl over simmering water and continue beating until they are warm, approximately 3-4 minutes. Remove from the heat and continue beating the eggs until they are light and tripled in volume, 4-5 minutes.
Fold 1/4 of the eggs into the chocolate to lighten the chocolate. Gently fold in remaining eggs. Pour immediately into prepared springform pan, and add hot water to the baking pan until the water comes halfway up the side of the springform.
Bake at 400 for 18 minutes, no longer. Torte will still look wet and jiggly in the middle, and that's okay.
Allow to cool to room temperature, approximately 45 minutes.
In small sauce pan or in microwave, heat the whipping cream just until bubbles form around the edge. Pour immediately over reserved chocolate chips, and let sit 3 minutes. Stir the cream and chocolate mixture until smooth, then pour over top of torte.
Refrigerate 6-8 hours before removing springform ring and serving. Garnish with fruit or whipped cream if desired.