In a large frying pan cook the apples with the sugar, cinnamon and water until they've softened (but not broken up).
Cut the tortillas in half. This should give you 12 triangles.
Place the tortilla semi - circle cut side away from you and paste one third with egg. Fold over the other side to make a triangular pouch, then fill with the cooked apple mixture. Seal the top with more brushed egg wash and press together to seal.
Lay them all on a baking tray and brush with butter. Bake for around 20 minutes until brown and crisp.