In a large pan, melt 25g/1oz of the butter. Add the sugar and apples, then put the lid on and cook over a gentle heat for about 10 minutes, stirring occasionally.
Remove the lid and cook for a further 5-10 minutes until the apples are broken down, but still with a few chunks for texture. Add the apricot jam and allow to cool.
Meanwhile, melt the remaining butter in a saucepan. Cut the slices of bread in half, and then in half again into strips. Dip each piece of bread into the melted butter and line a large mould (use a round cutter for the bottom of the mould - you can use individual moulds or one large one).
Once the mould is fully lined, spoon in the apple purée and top with another round of bread that has been dipped in melted butter. Place in the oven for 30 minutes, or until golden brown on top.
Remove from the oven and allow to cool slightly. Carefully turn out and serve immediately with custard.