In a large nonreactive saucepan, combine 2 1/2 cups of the milk, 1/2 cup of the sugar, and the vanilla over medium heat and whisk to dissolve the sugar. Bring to a gentle boil. In a large mixing bowl, beat the egg whites with an electric mixer on medium speed until soft peaks form. Add the remaining 1 tablespoon sugar and continue beating until stiff peaks form. With a wooden spoon, scoop 2 balls of the meringue into the simmering milk mixture. Poach the balls for 2 to 3 minutes, rolling them over with the spoon and basting them with the milk. When all sides are cooked (they are slightly firm to the touch), lift them out with a slotted spoon and set aside on a platter. Scoop 2 more balls from the remaining meringue and repeat the process.. The meringues can be stored for about 1 hour, loosely covered with plastic wrap, in the refrigerator until ready to use. In a small mixing bowl, combine the remaining 1/2 cup milk, the egg yolks, and cornstarch and whisk together. Slowly whisk 1/2 cup of the warm milk mixture that the meringues were cooked in, into the egg mixture, then pour back into the warm milk mixture in the saucepan. Whisking constantly, bring the mixture to a gentle boil and cook until it thickens enough to coat the back of a wooden spoon, about 2 minutes. Remove from the heat, pour into a glass bowl, and let cool to room temperature. Cover with plastic wrap, pressing the wrap down against the surface of the custard to keep a skin from forming. Refrigerate for at least 4 hours or up to 8 hours. To serve, gently stir the custard and spoon equal amounts into four dessert bowls. Set a meringue ball on top of each and drizzle with the caramel sauce.
In a small, heavy saucepan, combine the sugar and water and bring to a boil, stirring often. Cook, stirring occasionally, until the mixture is a deep caramel color and has the consistency of a thick syrup, 10 to 15 minutes. Remove from the heat. Stir in the cream, return the saucepan to high heat, and boil the sauce until regains the consistency of a thick syrup, about 2 minutes. Let cool. The sauce can be refrigerated until ready to use. Allow it to reach room temperature before using it. Yields: about 3/4 cup