Preheat your oven to 325 degrees
Bring 1 1/3 cups of heavy cream and 1/2 cup of whole milk to a simmer in a medium saucepan over medium heat
As soon as it simmers, remove the saucepan from the heat and whisk in 5 ounces of chocolate and 1 teaspoon of espresso powder
In a large bowl, whisk 5 large egg yolks with 3 tablespoons of granulated sugar
Very gradually add the melted chocolate mixture into the egg yolks and sugar while whisking constantly
Divide the ingredients equally between four 6 ounce ramekins
Tightly cover each ramekin with a small piece of tin foil and place them into a deep baking dish
Fill the cake pan with enough hot water to come half way up the sides of the ramekins
Bake on a middle rack at 325 degrees for 50 minutes or until the centers are lightly set
Carefully transfer the ramekins onto a heat proof surface, remove the tin foil and let the pots de crème sit at room temperature for 30 minutes before transferring them into the refrigerator
Chill the pots de crème for 2 or more hours before serving
Garnish with whipped cream and chocolate shavings