In a medium saucepan, whisk together 4 room-temperature eggs and ½ cup granulated sugar until pale and well-combined. Gradually stir in 2 cups of heavy cream, add 1 tablespoon of espresso powder and a pinch of kosher salt, mixing until incorporated.

In a double boiler over simmering water, add 8 ounces of bittersweet chocolate, stirring gently until completely melted, about 5–7 minutes. Ensure no water enters the bowl.

Slowly pour the custard mixture into the melted chocolate, stirring continuously to ensure an even blend.

Carefully divide the chocolate mixture into individual serving dishes or ramekins. Cover with plastic wrap and chill in the refrigerator for at least 4 hours.

Once set, remove from refrigerator and top with a dollop of espresso cream and a sprinkle of flaky salt before serving.