- 1 teaspoon unflavored gelatin
- 1 cup plus 2 tablespoons whole milk
- 6 tablespoons sugar, divided
- 6 tablespoons fresh lemon juice
- 1 1/2 teaspoons finely grated lemon peel
- Caramel Sauce (see recipe)
Lightly oil six 3/4-cup soufflé dishes or custard cups; set aside. Pour 1/4 cup water into small bowl. Sprinkle gelatin over; let stand until gelatin softens, about 15 minutes.
Meanwhile, whisk egg yolks and cornstarch in medium bowl until smooth. Combine milk and 3 tablespoons sugar in heavy medium saucepan; stir over medium heat until sugar dissolves and mixture comes to simmer. Gradually whisk 1/3 of hot milk mixture into yolk mixture. Pour mixture back into remaining milk mixture in saucepan. Whisk constantly over medium-high heat until mixture boils and thickens, about 2 minutes. Reduce heat to medium and whisk 2 minutes longer. Remove from heat; whisk in lemon juice and lemon peel. Add gelatin mixture; stir until gelatin dissolves.
Whisk egg whites and remaining 3 tablespoons sugar in medium bowl to blend. Set bowl over saucepan of simmering water (do not allow bottom of bowl to touch water); whisk constantly until instant-read thermometer inserted into mixture registers 140°F, about 2 minutes. Transfer egg white mixture to large bowl of stand mixer and beat until stiff peaks form. Fold egg white mixture into warm lemon custard in 3 additions. Transfer mixture to medium bowl; let stand 10 minutes to cool slightly.
Divide lemon custard among prepared soufflé dishes; level off tops with back of knife. Refrigerate soufflés uncovered overnight. DO AHEAD Can be prepared 2 days ahead. Cover and keep refrigerated.
Run small knife around soufflés to loosen. Place small plate atop 1 soufflé and invert. Using both hands, hold plate and soufflé dish tightly together and shake gently, allowing soufflé to settle on plate (if soufflé does not release from dish, place bottom of soufflé dish in 1 inch of warm water for 20 seconds). Repeat with remaining soufflés. Spoon room-temperature Caramel Sauce generously over top of each soufflé and serve.