5 ripe but firm bananas
1 tsp fresh lemon juice
397g/14oz can sweetened condensed milk
115g/4oz soft dark brown sugar
300g/10Β½oz chocolate oaty biscuits
25g/1oz coarsely grated plain chocolate or chocolate curls
75²µ/2Β½΄Η³ϊ butter
115g/4oz butter
450ml/16fl oz double cream