7 ounces finely chopped semisweet chocolate
4 tablespoons unsalted butter, plus for preparing the molds
1&1/2 teaspoons vanilla extract
3 large egg yolks
3 tablespoons warm water
1/2 cup sugar, plus 2 tablespoons
8 large egg whites, room temperature
1/2 teaspoon fresh lemon juice
Confectioners' sugar for garnish
- Brush 6 (6-ounce) ramekins with soft butter, then coat with sugar. Put the prepared ramekins in the freezer. (This can be done a day ahead.)
- Set an oven rack in lower third of the oven and preheat to 400 degrees F.
- Put the chocolate and butter in a medium heatproof bowl. Bring a saucepan filled with an inch or so of water to a very slow simmer; set the bowl over, but not touching, the water. Stir the chocolate occasionally until melted and smooth. Remove from heat and stir in vanilla extract. Set aside.
- Combine the egg yolks and warm water in the bowl of a standing mixer or large bowl and beat until frothy. Gradually add 2 tablespoons sugar, and continue beating until ribbons form, about 5 minutes. Very lightly fold the yolks into the chocolate mixture.
- Remove prepared ramekins from freezer. Put the egg whites in the bowl of a standing mixer, or large non-reactive bowl, add the lemon juice. Beat on medium until frothy; then gradually add the remaining 1/2 cup of sugar and increase speed to high. Beat until the whites hold a stiff but not dry peak.
- Fold about a third of the egg whites into the chocolate to lighten; then fold in remaining whites until blended. Gently ladle or spoon the souffle mixture into the ramekins, and place on a baking sheet. (Level off the surface with a straight edge, scraping any excess mixture back into the bowl.)
- Immediately bake until the souffle rises about 1 1/2 inches from the ramekins, and the tops are touched with brown, about 18 to 20 minutes. Remove from oven, dust with confectioners' sugar and serve immediately.