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.