Heat the milk in a saucepan and add the macaroni. Bring to a boil, stir and simmer for 10 minutes. Thicken with the cornstarch mixed with the water. Cook for 2 minutes. Add the sugar. If you wish to eat this dish cold, allow the pasta mixture to cool, then arrange in tall glasses. When ready to serve, heat the raspberry jam over low heat. Put a large scoop of ice cream into each glass, add a peach half and pour on the hot raspberry jam. Decorate with wafers and serve immediately before the ice cream melts. If you wish to serve this dish hot and enjoy the contrast between the hot pasta and cold ice cream, put the hot pasta into ovenproof dishes and keep warm. When ready to serve, top each with the ice cream, the peach halves and the hot jam. Then serve immediately.