Dessert: Chocolate Mousse

Recipe by Chef Dianne Rossmando This recipe is part of the Epicurious Online Cooking School, in partnership with the Culinary Institute of America. To watch it being made, and to learn how to make other dessert classics, check out the videos.

Ingredients

5 large egg yolks plus 4 large egg whites
2 tablespoons vanilla sugar (see Cooks' note)
2 shots (about 1 tablespoon) espresso coffee
8 ounces dark chocolate, melted and kept warm
1/4 cup sugar
3/4 cup heavy cream, whipped
Optional garnishes: Whipped cream, shaved chocolate, and fresh berries

Instructions

Set up a double boiler by filling a medium saucepan with 1 inch of water. Place the pan over moderate heat and bring the water to a simmer. In the bowl of a stand mixer, combine the egg yolks, vanilla sugar, and espresso. Place the stand mixer bowl over the pan of simmering water and whisk constantly until the sugar dissolves and the mixture is hot to the touch, about 2 minutes. Transfer the bowl to the stand mixer and, using the whisk attachment, beat on medium-high speed until pale, thick, and foamy (a whisk dragged through the mixture should leave a "ribbon" trail behind it), 10 to 15 minutes. (Do not discard the pan of simmering water.) Transfer the yolks to a large bowl then add the warm melted chocolate and gently fold to combine.
In a clean bowl of the stand mixer, combine the egg whites and sugar. Place the bowl over the pan of simmering water and whisk constantly until the sugar dissolves and the mixture is hot to the touch, about 2 minutes. Transfer the bowl to the stand mixer and, using the whisk attachment, beat on medium-high speed until the meringue is glossy and holds stiff peaks, about 5 minutes.
Add about one-third of the meringue to the chocolate–egg yolk mixture and fold until fully combined then gently fold in the rest. Gently fold in the whipped cream until evenly blended and no streaks remain.
Immediately spoon or pipe the mousse into a mold or glass and chill for at least 2 hours before serving. Garnish, if desired, with whipped cream, shaved chocolate, and fresh berries.