1. Melt 1/2 cup sugar and 1/4 c water in a small, heavy saucepan over medium-low heat. Let it boil and cook until it's nice and golden and reduced slightly in volume. (Basically: Make a simple syrup, but cook it further.)
2. Quickly pour into six small ramekins. The syrup will harden quickly. Let cool to the point where it's not too hot to touch.
3. Preheat oven to 350.
4. In a large bowl, combine four egg yolks, 1/2 cup sugar, 1 teaspoon vanilla and 1 big can (it's 12 ounces or so, I'm not sure) evaporated milk (NOT skim, NOT condensed). Mix with a whisk until well blended and a little frothy.
5. Pour into ramekins over the hardened syrup.
6. Put ramekins into a baking pan. Fill the pan with water up to the level of the custard (about 1.5 inches, I've found).
7. Bake at 350 until the custard is set. This took 45 minutes in my oven, but there's no rhyme or reason for anything with custard. Check after 30 minutes.
8. Remove from oven, cool for a bit on a rack, then refrigerate until cold. These keep for a day or two.
9. To serve, insert a knife around the custard, cut it loose, and invert on a plate. The syrup will have re-liquified, and will make a nice sauce. Garnish with berries if you wish.
This recipe can be doubled and baked in an 8-inch casserole (in a water bath, still), too.