Preheat the oven to 200°C.
Peel, core and dice the pears into bite-sized chunks.
Melt the knob of butter in a pan, add the pears and a splash of water then cook for a few minutes with the sugar and sultanas. Sprinkle over the custard powder, allow to bubble and thicken for a minute, then take off the heat and leave to cool.
Mix the breadcrumbs, ground almonds and sugar in a bowl. Unroll the puff pastry and cut the sheet in half to give you two equal pieces. Slice one of the pieces into 6 or 7 equally sized strips. Score a border gently around the edge of the other sheet, 2cm in from each side.
Scatter the breadcrumb and sugar mix into the centre square and spread into a thin layer, right to the edge. Spoon on the pear mixture, followed by small dollops of cranberry sauce.
Brush some of the beaten egg onto the outside border. Lay three strips of each pastry horizontally and 3 vertically so that they are evenly spaced out and (although optional) interwoven. Seal the strips on to the border edges with the beaten egg and brush the top of all strips with more egg.
Sprinkle with brown sugar and bake for about 20 minutes until crisp and golden. Serve with custard or ice cream. Serves 4