Boil 1½ glasses rice until half cooked. Bring to a boil 4 ½ glasses milk and 1½ spoons butter, add the rice, and boil until fully cooked. Divide the rice in half. To one half, add ⅛ to ¼ lb grated chocolate mixed with 2 spoons hot water and ⅓ glass sugar. Mix ⅓ glass sugar and 1 wineglass saffron infusion with the other half of the rice. Arrange alternate layers of rice in a mold greased with butter and strewn with rusk crumbs, making 6 layers in all.* Bake in the oven for fifteen minutes. To serve, turn out onto a platter and strew with sugar and cinnamon. Pour on chocolate, rum, or vanilla sauce.