Yields 8 servings
6 ounces bittersweet chocolate, finely chopped
1 1/3 cups heavy whipping cream
2/3 cup milk (I used 1%)
2 teaspoons espresso powder
1/2 teaspoon salt
6 large egg yolks
2 tablespoons white sugar
Whipped cream (optional)
Preheat oven to 300 degrees F.
Place chocolate in a heat-proof mixing bowl.
In a small saucepan, bring the cream, milk, espresso powder, and salt to almost a boil, stirring until the espresso powder is dissolved. Pour the hot mixture over the chocolate and whisk until the chocolate is melted and mixture is smooth.
In a separate bowl, whisk together the egg yolks and sugar. Add the warm chocolate slowly, stirring constantly. Pour the custard through a fine-mesh sieve into a clean bowl and cool completely, stirring occasionally. This will take about 15 minutes.
Divide the custard evenly between the ramekins. In a large baking pan, place the ramekins and fill the baking pan with enough boiling water to come up halfway on the ramekins. Cover the baking pan with aluminum foil, poking a few holes to let out the steam. Bake the custards in the hot water bath for 30 to 35 minutes, or until custards are set around the edges but still jiggle in the centers.
Transfer ramekins to a cooling rack and cool completely, uncovered, for about 1 hour. The custards will continue to set as they cool. Then, cover the ramekins and chill until cold, at least 3 hours.