In a heavy 3 quart saucepan, combine the milk and 1/4 cup of sugar. Bring to a gentle simmer over medium heat.Meanwhile, whisk the egg yolks, egg, cornstarch and remaining 1/3 cup of the sugar together in a mixing bowl until thick and yellow.Very gradually, whisk the hot milk mixture into the egg yolks. Once it is all added, pour the mixture back into the saucepan with the saucepan set over medium low heat.