Dark Chocolate Mousse Tart Recipe

Prepare and blind-bake crust

Preheat oven to 350°F (175°C). In a bowl, whisk together the all-purpose flour, almond flour, cocoa powder, granulated sugar, and salt until evenly combined. Add cold cubed butter and, using a pastry cutter or your fingertips, cut the butter into the dry ingredients until the mixture resembles coarse crumbs with some pea-sized pieces remaining. Add the egg and vanilla and stir until the dough comes together. Press the dough evenly into the bottom and up the sides of a 9-inch tart pan with removable bottom (use your fingers or the bottom of a measuring cup to compact). Chill the crust in the refrigerator for 15 minutes to relax the gluten and firm the butter.

Line the chilled crust with parchment or foil and fill with pie weights or dried beans. Bake blind for 15 minutes. Remove weights and parchment and bake another 8–10 minutes until set and slightly firm to the touch. The crust will be fragrant and the edges set. Let cool completely on a wire rack. If the crust puffs, press gently with a spatula while still warm to flatten.

Melt chocolate

Place the chopped dark chocolate and 2 tablespoons unsalted butter in a heatproof bowl set over a simmering water bath (bowl should not touch the water) or microwave in 20-second bursts, stirring between, until smooth. Remove from heat and let cool slightly to about 100–110°F (warm but not hot).

Temper egg yolks

Whisk the egg yolks lightly in a small bowl. Slowly add 1 tablespoon of the warm melted chocolate to the yolks, whisking constantly to temper them, then whisk the tempered yolks back into the bowl of melted chocolate until fully incorporated. Stir in 1/2 tsp vanilla and a pinch (1/8 tsp) kosher salt.

Whip egg whites

In a clean bowl with clean beaters, whip the egg whites to soft peaks. Gradually add 1/4 cup granulated sugar while whipping and continue until glossy, medium-stiff peaks form.

Whip cream

In a separate chilled bowl, whip the cold heavy cream to soft peaks (not too stiff).

Fold the whipped cream gently into the chocolate mixture in two additions until mostly incorporated. Then fold in one-third of the whipped egg whites to lighten the mixture, followed by the remaining whites, folding gently until no streaks remain. Work quickly but gently to keep the mousse airy.

Pour or spoon the mousse into the cooled almond crust, smoothing the top with an offset spatula. Chill the tart in the refrigerator for at least 4 hours or preferably overnight to set properly.

Make caramel

About 30–45 minutes before serving (so it cools but stays pourable), make the caramel. In a medium, heavy-bottomed saucepan, combine 3/4 cup granulated sugar and 2 tablespoons water. Swirl gently to combine but do not stir. Heat over medium-high until the sugar melts and turns an amber color — watch closely to avoid burning. As it browns, swirl the pan occasionally. When it reaches a deep amber, remove from heat and carefully add the 2 tablespoons butter, stirring until melted. Slowly pour in the warm 1/4 cup heavy cream while stirring (mixture will bubble vigorously). Stir until smooth. Add 1/4 tsp sea salt (or to taste). Allow to cool slightly until thick but still pourable.

If you prefer a thinner caramel for drizzling, let it cool a few minutes less; for a thicker drizzle, cool longer. Do not overcool to solid.

When the mousse has fully set, spoon or drizzle the warm (but not hot) caramel over the center of the tart, leaving a border of mousse visible. Use a spoon to spread the caramel gently — a shallow pool is ideal so it doesn't slide off.

Make chocolate curls

To make curls: warm a metal baking sheet in a low oven or hold a warm offset spatula, then scrape a thin block of the 2 oz dark chocolate across a warm metal surface with a vegetable peeler or the edge of a knife to form curls. Alternatively, shave with a Microplane for fine shavings. Scatter curls over the caramel and mousse.

Scatter the toasted sliced almonds and sprinkle a few flakes of fine sea salt over the tart for contrast. Chill briefly (10–15 minutes) to let the caramel settle, then serve slices at room temperature.