For the Cinnamon Dulce de Leche, mix sweetened condensed milk, roasted cinnamon and vanilla in large microwavable bowl. Microwave on MEDIUM (50% power) 4 minutes, stirring after 2 minutes. Microwave on MEDIUM-LOW (25% power) 12 minutes, stirring every 4 minutes or until milk is thick and caramel colored. Carefully remove bowl from microwave with pot holders. Set aside until ready to serve. (Sauce will thicken upon standing).
For the Bittersweet Chocolate Torte, preheat oven to 350°F. Butter a 9-inch springform pan. Dust with cocoa powder. Set aside. Place butter and cream in medium saucepan on medium-low heat. Simmer until butter is melted. Remove from heat. Add chocolate; stir until chocolate is completely melted and mixture is smooth.
Mix eggs, sugar, cocoa powder, vanilla and roasted cinnamon in large bowl with wire whisk until well blended. Whisk in chocolate mixture. Pour into prepared pan.
Bake 35 to 40 minutes or until cake slightly puffed and center is set. Cool cake in pan on wire rack 1 hour. (Cake will fall in center slightly during cooling).
Use a knife to loosen sides of cake from pan before removing rim. Drizzle with warm Cinnamon Dulce de Leche.