Peel the oranges and cut into thick slices, reserving any juice. Place the sugar in a heavy-based saucepan with the measurement water. Cook over a medium heat until it starts to turn a dark brown colour.
Remove from the heat and carefully pour in the liqueur (it will spit). The caramel will harden, so return to a low heat and cook until melted again. Stir in the oranges and any juice, then spoon into glass bowls and serve.