This is Thomas Keller's famous French Laundry dessert. The batter can be made up to 1 hour ahead and left at room temperature to be baked last minute. Or, make the batter well in advance, freeze it in the ramekins and put them straight into the oven when ready to bake. From the freezer, the baking time is 20 minutes.

GANACHE TRUFFLES:

• 2 ounces semi-sweet chocolate, chopped
• 1/4 cup heavy cream

Place the chopped chocolate in a bowl. Bring the cream to a boil and pour it over the chocolate. Slowly stir until smooth. Transfer the mixture into a shallow glass dish and let it cool slightly, about 10 minutes, then place it in the freezer to chill for 1 hour.

Scoop out balls using a 1 teaspoon measuring spoon and shape them so that they're round. Chill until ready to use.

CAKE:

• 14 ounces bittersweet chocolate
• 2 1/2 sticks unsalted butter
• 1 tablespoon all-purpose flour
• 10 egg yolks
• 7 tablespoons granulated sugar
• Non-stick Cooking Spray
• Powdered Sugar, for dusting

Preheat the oven to 375°F.

Melt the chocolate and butter in the top of a double boiler. Stir in the flour and remove from the heat to cool slightly.

Whip the yolks in the bowl of an electric mixer and slowly add the sugar until the whisk leaves a thick ribbon that stays on top of the batter when it is lifted out, about 5 minutes. Pour the chocolate into the yolk-sugar mixture and gently fold them together.

Spray 10 (1/2-cup) ramekins with cooking spray. Half-fill each with chocolate batter, place 1 ganache ball in the center and then continue filling to the top with more batter. Place the ramekins on a rimmed baking sheet. (The recipe can be made ahead to this point up to 1 hour in advance and stored at room temperature, or 1 week in advance and frozen, tightly covered.)

Bake the cakes until they begin to pull away from the sides of the ramekins, 12 to 15 minutes. Dust with powdered sugar.

Makes 10 Soufflés