Grease 9 dariole or baba moulds. Sift the flour and salt into a warm basin. Cream the yeast with a pinch of castor sugar, and add to it the gill of warm milk. Mix this into the flour to form a soft dough. Beat well until the dough leaves the sides of the basin clean. Cover the basin with a damp cloth and leave the dough to rise in a warm (but not hot) place until about twice its size. When the dough has risen sufficiently add 2 eggs, the melted butter and castor sugar, beat well in. Then add the rest of the eggs and the currants and beat again for 5–10 min., until the dough is smooth and glossy. Halffill the moulds with the mixture. Put them in a warm place until the mixture has risen to the top of the moulds. Bake in a fairly hot oven (425 ° F., Gas 7) for about 20–25 min. until brown and firm.
Put the granulated sugar and water into a pan with the thinly peeled lemon rind. Boil for 10 min., add the rum and sherry; strain.
Reheat the syrup. Soak the babas in it for a minute; lift them out and serve immediately, with the syrup poured round.