This recipe was originally posted in December 2009. I thought it needed an image makeover and the recipe is so amazing that I am re-posting it so that those of you who are new to the blog are aware of how important it is to make this. Immediately.

This aptly named dark chocolate mousse may be the death of you, but it’s oh, so worth it. I gave a dish to my mom yesterday to take home. She wrote me an email today asking me never to do that again. She takes one bite and then completely loses self control around this amazing dessert. And it’s no wonder. This recipe is from Cooks Illustrated – and boy do they know how to make a mean chocolate mousse.

Before we begin, there is an important note for people who are not familiar with the recipe term to “fold one ingredient into another.” By this, they are saying DO NOT MIX and especially don’t use a whisk. You’ve worked to get lots of air into your egg whites or whipping cream because those trapped air bubbles are what make mousse so light and fluffy. You don’t want lose those air bubbles, so when it comes time to add something that has been aerated to the chocolate, use a rubber spatula and literally pretend you are folding one part of the chocolate over to another. At first you’ll feel that all you’re doing is making a big mess (because honestly, you are making a big mess!), but as you keep gently folding one corner of your chocolate over to the opposite side, you’ll notice the chocolate mixture becoming more silky. End result – a mousse that feels light and fluffy!

dark chocolate mousse

8 oz bittersweet chocolate
2 tbsp cocoa powder (preferably Dutch-processed)
1 tsp instant espresso powder (I don’t like the taste of espresso… if you’re in the same boat, DO NOT omit this! Just use 3/4 tsp instead)
5 tbsp water
1 tbsp brandy
2 large eggs, separated
1 tbsp sugar, divided
1/8 tsp table salt
1 cup heavy cream, chilled (plus extra to make homemade whipped cream to dollop on top!)

Melt chocolate, cocoa powder, espresso powder, water, and brandy in microwave, stopping after each minute to stir the contents. Once the chocolate is melted, set aside.

Whisk egg yolks, 1 1/2 teaspoons sugar, and salt in medium bowl until mixture lightens in color and thickens slightly, about 30 seconds.

Pour melted chocolate into egg mixture and whisk until combined. Let cool until just warmer than room temperature, 3 to 5 minutes.

In clean bowl of standing mixer fitted with whisk attachment, beat egg whites at medium-low speed until frothy, 1 to 2 minutes. Add remaining 1 1/2 teaspoons sugar, increase mixer speed to medium-high, and beat until soft peaks form when whisk is lifted, about 1 minute. Detach whisk and bowl from mixer and whisk last few strokes by hand, making sure to scrape any unbeaten whites from bottom of bowl.

Using whisk, stir about one-quarter of beaten egg whites into chocolate mixture to lighten it; gently fold in remaining egg whites with rubber spatula until a few white streaks remain.

In now-empty bowl, whip heavy cream at medium speed until it begins to thicken, about 30 seconds. Increase speed to high and whip until soft peaks form when whisk is lifted, about 15 seconds more.

Using rubber spatula, fold whipped cream into mousse until no white streaks remain.

Spoon into 6 to 8 individual serving dishes or goblets. Cover with plastic wrap and refrigerate until set and firm, at least 2 hours. (The mousse may be covered and refrigerated for up to 24 hours.) Dollop with freshly sweetened whipped cream before serving.