Preheat oven to 350 degrees F. Adjust oven rack to center position. Lightly butter (or use non-fat vegetable spray) six (6-ounce) custard cups and set them into a large baking dish. Tip: Place a non-stick baking mat (called a silpat) or a tea towel in the bottom of your baking dish to both insulate and keep the ramekins firmly in place.
In a large bowl, beat eggs slightly; add sugar, vanilla extract, and salt; beat until dissolved. Mix in hot milk until blended. Pour egg mixture into prepared custard cups. Sprinkle with nutmeg or cinnamon.
Bring the water for the water bath to a light simmer on top of the stove; carefully pour hot water into the baking pan to come at least half-way up the sides of the custard cups. The most common mistake people make in baking a custard is not putting enough water in the hot-water bath. The water should come up to the level of the custard inside the cups. You must protect your custard from the heat. Carefully pour hot water into the baking pan to come up the sides of the custard cups.
Definition of Water Bath or Bain-Marie (bahn mah-REE) - A hot water bath or bain-marie are used to cook custards and baked eggs in the oven without curdling or cracking, and also used to hold sauces and to clarify butter. Water baths are most often used for egg-based dishes. The proteins in the eggs are very heat sensitive and only need to be warmed to cook thoroughly. They will start to get firm at only 145 degrees F. Cooking them with a slow, gentle heat keeps the eggs soft and smooth.
Bake 25 to 30 minutes or until set around the edges but still loose in the center. The cooking time will depend largely on the size of the custard cups you are using and the altitude you are at. Begin checking at a half hour and check back regularly. When the center of the custard is just set, it will jiggle a little when shaken, that is when you can remove it from the oven. If using a digital instant-read thermometer, inserted in the centers, the internal temperature should register approximately 170 to 175 degrees F. Begin checking temperature about 5 minutes before recommended time.
High Altitude Cooking: Custards with a water bath will often need additional water during the baking time. Also your custards will need a longer cooking time because the altitude causes the water to evaporate faster.
Remove from oven and immediately remove cups from water bath; cool on wire rack until room temperature. Cover with plastic wrap, and refrigerate at least 2 hours or up to 2 days.
Makes 6 servings (depending on size of custard cups).
* The amount of eggs used can vary according to your needs. When I make custard for dessert, I usually use 4 eggs. When making for breakfast, I increase the recipe to 6 eggs.
Old-Fashioned Baked Custard Recipe: https://whatscookingamerica.net/bakedcustard.htm