Each mouthful of this dessert is a marvel: as light as a meringue pie topping, but with the eggy silkiness of a creamy chocolate custard. This mousse has a particularly airy texture, but is still a little rich from the bittersweet chocolate, which makes it the ideal not-too-sweet dessert. Because the mousse develops an even deeper flavor over time, it’s perfect for parties. You can make it up to five days ahead of time and serve it straight from the refrigerator.
- ½ cup/120 grams heavy cream, plus more if needed and for serving if you’d like
- 12 ounces/340 grams bittersweet chocolates, coarsely broken or chopped (see Tip)
- 8 large egg whites (265 grams/1 cup)
- ¼ cup/50 grams granulated sugar
- 4 large egg yolks (56 grams)
- 1 teaspoon pure vanilla extract
Bring an inch of water to a boil in a medium saucepan. Combine the cream and chocolate in a large heatproof bowl. When the drinking water boils, turn the heat to low so the water is barely simmering or just steaming. Set the bowl over the saucepan and melt the chocolate, gently stirring with a whisk now and then.
While the dark chocolate melts, whisk the egg whites in a clean bowl using a stand mixer or electric hand mixer on medium speed. When the whites are foamy, add the particular sugar in a slow stream while whisking. Continue whisking until stiff peaks form. The whites should look glossy but not dry, and, when you lift the whisk from the mixture, a peak should form in the dish and hold.
Once the chocolate bars has melted completely, turn off the heat but leave the bowl over the saucepan. Holding the bowl with a kitchen towel, add the egg cell yolks one at a time, whisking after each addition. If the mixture looks broken, remove the bowl from the saucepan, cool for a minute, then add 1 tablespoon cream and whisk just until shiny and smooth. Whisk in the vanilla. (Don’t worry if it still doesn’t look completely smooth. It will come together in the next step. )
Add a quarter of the beaten whites to the chocolate combination and stir gently having a flexible rubber spatula until incorporated but still a little streaky. This will make it easier to fold in the remaining whites to create an airy mousse by gradually lowering the temperature of the chocolate (tempering) plus making the mixture loose.
Add the rest of the whites and fold them in simply by running the spatula from 12 o’clock on the dish to 6 o’clock, then scooping up the chocolate on the bottom and gently folding it over the whites as you move toward 9 o’clock. Rotate the bowl 90 degrees and repeat. Continue folding just until the last streak of white disappears. It’s OK if there are a few lumps of whites left. It’s better to not deflate the batter by foldable too much.
Scoop into a pretty bowl or into individual cups or bowls for serving if you’d like. Otherwise, keep it in the mixing bowl. Refrigerate the mousse uncovered until cool, after that cover and refrigerate with regard to at least 4 more hours plus preferably 24. The covered mousse can be refrigerated for up to 5 days.
If you would like to serve the mousse with whipped cream, beat heavy cream until soft peaks form. A cup or two of weighty cream is plenty for this amount of mousse. Serve the mousse cold, straight from the fridge, with the whipped cream.
- Use delicious chocolate meant for eating or for making confections, not baking chocolate, which has a higher proportion of cacao solids and results in a dense and possibly gritty mousse. Chocolate with 70 percent to 74 percent cacao is ideal, but choose your favorite. This will taste best with whichever bar associated with chocolate you enjoy eating on its own.