Mix the ground almonds, icing sugar and egg white together to form the marzipan paste. (Whisking the egg white will make it easier to measure out).
Cut off 425g of pastry from the block and roll out to a 36cm square on a floured surface, trim and cut into 4 x 18cm squares.
Peel and core the first apple and stuff with a ¼ of the marzipan (you can do this from the top and bottom). Doing one at a time will prevent the apples from going brown.
Place the apple in the centre of one of the squares.
Brush a little water on the outer edges of the pastry and draw up one corner to meet the middle, then do the same with the next corner sealing and tucking in the pastry as you go following your way round in one direction until you reach the end.
Repeat above with the next 3 apples.
To decorate, roll out the pastry trimmings and cut straight lines down and diagonally across to make diamond shapes and score with a knife to make them look like leaves. You need 16.
Using the apple corer cut out 4 circles.
Decorate the apple dumplings with the leaves using a little water to seal and finish with a little circle of pastry on top.
Place on a lightly greased baking tray and pop in fridge for 20 minutes.
Pre-heat oven to 190⁰C.
Brush the apple dumplings with egg wash and sprinkle with caster sugar.
Place in the middle of oven for 40 minutes turning halfway through.
Serve hot with cream, ice cream or custard.
Can also be reheated if needed later (about 15 – 20 mins at 150C⁰).