Tiramisu Chocolate Mousse

2 tablespoons brewed espresso

1 tablespoon unsalted butter

3 ½ ounces dark chocolate, broken into small pieces

2 tablespoons Marsala wine or rum

2 egg yolks

4 teaspoons white sugar

2 tablespoons mascarpone cheese

¾ cup heavy cream

Combine espresso and butter in the top of a double boiler over simmering water.

Place dark chocolate pieces in the espresso mixture; cook without stirring until chocolate starts to melt, about 3 minutes. Whisk chocolate and espresso mixture until well combined. Remove from heat and set aside.

Combine Marsala, egg yolks, and sugar in a saucepan over medium-low heat, whisking constantly until frothy and thickened, 3 to 5 minutes. Remove from heat.

Stir mascarpone cheese into marsala mixture.

Combine chocolate mixture with mascarpone mixture. Cool to room temperature.

Whip heavy cream in a bowl until soft peaks form, 2 to 3 minutes.

Fold half of whipped cream into cooled chocolate mixture.

Fold second half of whipped cream into chocolate mixture. Cover with plastic wrap and chill in refrigerator for at least 2 hours.