PREHEAT oven to 425° F. Generously butter six 6-ounce ramekins or custard cups with two tablespoons butter. Combine flour and cinnamon in small bowl; set aside.
STIR 3/4 cup butter and chocolate in medium, heavy-duty saucepan over low heat until chocolate is melted and mixture is smooth. Remove from heat. Beat eggs, egg yolks, sugar and vanilla extract in large mixer bowl until thick and pale yellow, about 8 minutes. Fold 1/3 of chocolate mixture into egg mixture. Fold in remaining chocolate mixture and flour mixture until well blended. Divide batter evenly among prepared ramekins. Place on baking sheet.
BAKE for 11 to 13 minutes or until sides are set and 1-inch centers move slightly when shaken. Remove from oven to wire rack.
TO SERVE, run a thin knife around top edge of cakes to loosen slightly; carefully invert onto serving plates. Lift ramekins off of cakes. Spoon Caramel sauce over each cake. Sprinkle lightly with sea salt. Serve immediately.