Preheat oven to 225°.
Place egg yolks in mixing bowl.
Heat cream, half-and-half and granulated sugar until warm.
Slowly stir into the yolks.
Place six ramekins in a tray and fill with above mixture to the top.
Fill tray two-thirds of the way up with hot water.
Bake for 1-1/2 to 2 hours, or until set. Remove and chill.
Place one tablespoon of Demerara sugar on the top of each ramekin.
Glaze under a very hot broiler until brown, chill again and serve.
The reason the oven temperature is kept low in the baking of this delicious dessert is to keep the water from boiling. If the water boils, your eggs may scramble when cooking.