Step by step

Method

4 steps

1. 1

   Melt 6 oz chopped semisweet or bittersweet chocolate with 2 tablespoons unsalted butter and ¼ cup of the heavy cream (you'll use 1½ cups total) over low heat or in short microwave bursts. Stir until smooth, then cool to room temperature — still fluid, not warm to the touch. Warm chocolate will melt the whipped cream and leave you with soup.

2. 2

   Whip the remaining cold cream (1¼ cups) with 3 tablespoons powdered sugar, 1 teaspoon vanilla, and a pinch of salt to soft-stiff peaks — peaks that hold but still curl at the tip.

3. 3

   Fold one-third of the whipped cream into the chocolate to lighten it (it may look streaky — that's fine). Then fold in the rest until no white streaks remain and the mousse looks airy and uniform. Don't stir hard or you'll knock out the air.

4. 4

   Spoon into 4–6 glasses or ramekins. Chill at least 1 hour until softly set. Top with shaved chocolate or berries. You want light, spoonable chocolate mousse that holds soft peaks on the spoon — not a dense ganache or a runny chocolate cream.