Preheat oven to 350 degrees. Place four 4 oz Ball jars (or other small ramekins) in a deep baking dish or roasting pan. Fill the pan with water so that it reaches the middle of the jars.

Whisk egg yolks and vanilla together in a small mixing bowl.

In a small saucepan heat chocolate, sugar, cream and milk over low-medium heat. Stir constantly and continue heating just until chocolate is melted and mixture is smooth. Remove from heat.

While chocolate is still very warm, pour chocolate mixture slowly into eggs. Whisk vigorously to combine. Mixture should be smooth. Pour into individual serving bowls.

Bake jars in water bath until just set, about 20 minutes. Remove cups from water and refrigerate for at least 1 hour. Serve chilled – plain or topped with fresh whipped cream.