Cappuccino Mousse Pie Recipe

Prepare crust

Preheat oven to 350°F (175°C). Lightly butter a 9-inch (23 cm) removable-bottom tart pan or pie pan. In a medium bowl, combine chocolate wafer crumbs, cocoa powder, granulated sugar, and salt. Pour melted butter over the dry mixture and stir until evenly moistened — the texture should hold when pressed.

Press crumbs firmly into the bottom and up the sides of the prepared pan to form an even crust layer (about 1/3-inch thick). Use the bottom of a measuring cup to compact crumbs tightly.

Bake crust for 8–10 minutes until fragrant and set. Remove from oven and cool completely on a wire rack while you make the filling. Reduce oven temperature to 325°F if keeping oven on, or leave off if not needed.

Bloom gelatin

Sprinkle gelatin over cold water in a small bowl and let sit 5 minutes to bloom.

Warm milk and dissolve espresso

In a small saucepan, heat the whole milk over medium until steaming but not boiling. Remove from heat and whisk in the instant espresso powder (and optional instant coffee granules) until fully dissolved. Set aside.

Temper egg yolks

In a heatproof bowl, whisk the egg yolks with 1/4 cup of the granulated sugar until slightly thickened and pale. Slowly pour one-third of the hot milk-espresso mixture into the yolks, whisking constantly to temper. Then pour the tempered yolks back into the saucepan with the remaining milk mixture.

Cook custard

Return saucepan to medium-low heat and cook, 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). Do not boil. Remove from heat immediately.

Add chocolate and gelatin

Pour the hot custard over the chopped semisweet chocolate in a bowl. Let sit 1 minute to soften the chocolate, then whisk until smooth and glossy. Whisk in the bloomed gelatin until dissolved, then stir in vanilla extract and the remaining 1/2 cup granulated sugar (adjust sweetness to taste). Set aside to cool to room temperature, stirring occasionally to prevent skin formation.

Whip cream and fold

In a chilled bowl, whip 1.5 cups heavy cream to soft peaks using a whisk or electric mixer. Fold one-third of the whipped cream into the cooled chocolate-coffee base to lighten it, then gently fold in the remaining whipped cream until fully combined and airy. The mousse should be smooth and mousse-like without streaks.

Pour the coffee mousse into the cooled crust, smoothing the top with an offset spatula. Tap the pan gently on the counter to remove air pockets. Cover loosely with plastic wrap and refrigerate at least 4 hours, preferably overnight, until set.

Prepare whipped topping

About 15–30 minutes before serving, combine heavy whipping cream, confectioners' sugar, and vanilla extract in a chilled bowl. Whip to medium-stiff peaks.

Spread or pipe the whipped cream over the set mousse pie. Dust lightly with cocoa powder and garnish with chocolate shavings if desired.

Refrigerate for 15–20 minutes to let the topping settle. When ready to serve, run a thin knife around the pan edge, release the removable bottom, slice with a hot, dry knife for clean slices, and serve chilled.