Set large pan of water in oven, with mold in pan. Use a 1 1/2-quart oval casserole.
In top of a double boiler over hot water, melt chocolate in the 1/4 cup water.
Add to the milk beaten with the yolks and vanilla extract and the 1/2 cup of the
sugar. Beat well.
Caramelize 1/2 cup sugar over high heat in a small saucepan, stirring hard. When
sugar begins to melt, reduce heat and continue stirring until sugar has all melted
and is a light tan. Do not burn — it will turn bitter. Pour it into the bottom
of the mold, and tilt to cover the bottom. Pour the chocolate mixture into the mold.
Bake for 1 hour.
Cool thoroughly. (Make it the day before use and let it firm in
To serve, slide a spatula around the upper edge of the custard to loosen; place
a large platter with some depth over the casserole, and invert carefully. Let mold
remain about 15 minutes so all the caramel sauce can drip down.