Belgian Chocolate Mousse Recipe

Melt chocolate and butter

Place the chopped dark chocolate and butter in a heatproof bowl. Set the bowl over a small saucepan of simmering water (double boiler), making sure the bowl does not touch the water. Stir gently until the chocolate and butter are fully melted and smooth, 3–5 minutes. Remove from heat and set aside to cool slightly (but not harden).

Warm cream for tempering yolks

Pour 2 cups cold heavy cream into a small saucepan and warm over medium-low heat until it is steaming and small bubbles form at the edge, about 3–4 minutes. Do not boil. Remove from heat.

Temper egg yolks

In a medium bowl, whisk the 4 egg yolks together with 1 tablespoon granulated sugar and 1 teaspoon vanilla until smooth and slightly pale, about 1 minute. Slowly pour about one-third of the hot cream into the yolks in a slow steady stream while whisking constantly to temper. Then pour the tempered yolk mixture back into the saucepan with the remaining warm cream, whisking to combine.

Cook custard gently

Return the saucepan to low heat and cook gently, stirring constantly with a wooden spoon or heatproof spatula, until the mixture thickens slightly and coats the back of the spoon (about 170–175°F / 77–80°C). This should take 2–4 minutes — do not let it boil. Remove from heat.

Combine custard with chocolate

Pour about one-quarter of the warm custard into the melted chocolate and stir vigorously to loosen the chocolate (creates a smooth emulsion). Then pour the chocolate-custard mixture back into the remaining custard and whisk until fully combined and glossy. Stir in a pinch of sea salt. Let the mixture cool to room temperature, stirring occasionally, about 15–20 minutes.

Whip cream

While the chocolate-custard cools, chill a medium bowl and whisk or beaters if possible. Pour 1 cup chilled heavy cream and 1 teaspoon powdered sugar (optional) into the bowl. Whip to soft-medium peaks: the cream should hold its shape but still be smooth and slightly jiggly, about 2–3 minutes on medium-high speed with an electric mixer or slightly longer by hand.

Fold whipped cream into chocolate mixture

Check that the chocolate-custard is cooled to room temperature (warm will deflate whipped cream). Spoon about one-third of the whipped cream into the chocolate mixture and fold gently to lighten it (use a spatula and cut-and-fold motion). Add the remaining whipped cream in two additions, folding gently each time until no streaks remain and the mousse is uniform and airy. Be careful not to overfold.

Portion and chill

Divide the mousse among 6 serving glasses or ramekins using a spoon or piping bag. Smooth tops if desired. Cover each vessel (or cover the tray) and refrigerate at least 2 hours, preferably 3–4 hours, until set and chilled.

Garnish and serve

Just before serving, dust the mousse lightly with cocoa powder or top with shaved chocolate. Optionally add a small dollop of extra whipped cream. Serve chilled.