No funny business here: This chocolate mousse is simply melted chocolate that's thickened with egg yolks and lightened with whipped egg whites. Like your favorite chocolate bar is frolicking among the clouds.
If you're comfortable whipping egg whites and incorporating them gently, as to not deflate that hard-earned air, then the recipe will be a cinch. Perhaps that's because Dorie, when she implored her friend Martine for the ingredients and instructions, was handed a Nestlé chocolate bar: All of the information was on the back.
Melt the chocolate in a medium heatproof bowl placed over a small pot of simmering water. Stir until the chocolate is melted and smooth.
Remove bowl from water, add the egg yolks, and whisk until smooth.
Using an electric beater, beat the egg whites and a pinch of salt until you have soft peaks. Gradually add 1 1/2 teaspoons sugar, beating constantly, until whites are glossy with medium-firm peaks.
Use a spatula to fold 1/4 of the egg white mixture into the chocolate mixture to lighten it. Then fold the remaining whites into the chocolate until just incorporated, being careful not to overmix or deflate the mixture.
Divide mousse among 4 bowls. Cover and chill until set, about 4 hours (and up to 1 day in advance).
When ready to serve, beat the cream with the remaining teaspoon of sugar until soft peaks form. Spoon over mousse, sprinkle with chocolate shavings, and eat.