In a kettle of boiling water blanch the peaches for 1 minute and transfer them to a bowl of ice and water to stop the cooking. Peel and pit the peaches and in a food processor or blender puree them. In a large bowl stir together the sugar, the milk, and the cream, stirring until the sugar is dissolved. , stir in the puree and the vanilla, and freeze mixture in an ice cream freezer according to manufacturer instructions. Makes about 1 1/2 quarts.