Peel and core the apples and cut into slices. Melt ½ oz (15 g/⅛ stick) butter in a stainless steel saucepan with 1 tablespoon of water. Toss in the apples and 4 ozs (110 g/½ cup) sugar, cover and cook over a gentle heat until soft. Remove the lid if they are getting too juicy—you’ll need a dry purée. Stir well, taste and add a little more sugar if necessary. Allow to cool for a few minutes and then beat in the egg yolks.
Meanwhile clarify the butter.
Preheat the oven to 200°C/400°F/regulo 6.
Cut the crusts off the loaf and carefully cut the bread into thin slices, ¼ inch (5 mm) thick approx. Brush the tin with some butter and sprinkle with 1 oz (30 g/⅛ cup) approx. castor sugar. Cut 2 large pieces of bread, one to line the base of the tin and one for the top of the tin. Dip both sides of the bread into the melted butter. Line the base first, then line the sides of the tin. Cut the last of the bread into manageable-sized pieces, 1½ inches (3.5 cm) wide approx., and line the sides with the buttery bread, making sure there are no gaps. Seal all the joins with lightly beaten egg whites. Fill the centre with the sweetened apple purée and put a lid of buttery bread on top. Bake in the preheated oven for 20 minutes approx. and then reduce the heat to 190°C/375°F/regulo 5 for a further 40 minutes approx. or until the bread is crisp and golden brown. Leave to settle for 10 minutes or so before turning it out of the tin.
Serve warm with a bowl of softly whipped cream—heavenly!