How to Make It
Preheat the oven to 325°. Set four 8-ounce ramekins in a small roasting pan. In a small saucepan, combine 1/2 cup of the sugar with the water and bring to a boil over moderate heat, stirring to dissolve the sugar. Simmer over moderate heat until a rich brown caramel forms, about 15 minutes. Quickly pour the caramel into the ramekins to coat the bottoms.
In a medium saucepan, combine the milk with the vanilla bean seeds and bring to a boil over moderate heat; reserve the bean for another use. Remove from the heat. In a medium bowl, whisk the remaining 1/2 cup of sugar with the egg yolks and eggs. Slowly whisk in the hot milk. Strain the custard through a fine sieve back into the pan and pour it into the ramekins.
Add enough hot water to the roasting pan to reach halfway up the sides of the ramekins. Bake the custards for about 50 minutes, or until barely set. Transfer the ramekins to a rack and let cool to room temperature. Cover and refrigerate overnight.
Run a thin knife around the edges of the custards, top with plates and invert, letting the caramel run onto the plates.