Combine the milk, cream and 1 cup of the sugar in a heavy saucepan. Bring to a simmer over medium heat. Meanwhile, whisk together the egg yolks and the remaining 1/4 cup of sugar.
Remove the milk mixture from the heat and add a little to the egg yolk mixture to warm it, whisking constantly to keep the yolks from curdling. Pour the yolk mixture into the hot milk mixture, whisking the milk constantly as you pour.
Return the custard to the stove and cook it over medium-low heat, stirring constantly with a wooden spoon, until it thickens enough to coat the back of a spoon, about 5 minutes.