Wash the oranges and boil them whole for 1½ hours, or until they are very soft. Beat the eggs with the sugar. Add the orange blossom water, baking powder and almonds and mix well. Cut open the oranges, remove the seeds and purée in a food processor. Mix thoroughly with the egg and almond mixture and pour into a 23cm (9 inch) oiled cake tin dusted with matzo meal or flour – preferably non-stick and with a removable base. Bake in a preheated 375F/190C/gas 5 oven for an hour. Let it cool before turning out.