Place flour, salt, baking powder, and sugar in a mixing bowl. Sift to mix and then rub in shortening. Mix to a dough with ice-cold water. Roll out on a well-floured pastry board one-quarter inch thick. Now cover with the prepared peaches and then sift over sugar and cinnamon.
Roll as for jelly roll, tucking the ends in securely. Place in a well-greased and floured pan and bake in a moderate oven for forty-five minutes. Baste every ten minutes with syrup, water, and nutmeg. Stir to thoroughly mix before basting the roll.
Remove the roll to a large platter when baked and serve cold, with crushed and sweetened peaches in place of a sauce.
Select the fully ripe peaches and cut into thin slices; if they are clinging stones, cut into small pieces.