Rinse the oranges thoroughly and cut them into slices, discarding the end pieces that do not contain pulp. Place the orange slices in a shallow dish in layers with the sugar sprinkled over them and leave for one night.
A day later, place the fruit in a large saucepan along with any juice that has escaped.
Bring the contents to a leisurely boil and simmer over low heat until the orange slices are soft and translucent.
Fold in the brandy and remove the saucepan from the heat. Pour the fruit into preserving jars along with the syrup and seal the jars.
Preserved fruits are usually more substantial and considerably sweeter than jams, and the fruits do not need to be crushed. They are served as a dessert with cream cheese or whipped cream.