Peel and core apples, boil until tender, allow to cool then slice finely. Lightly beat eggs, gradually adding 1/2 cup of water, flour, sugar and cinnamon, beat until smooth. Pour batter into a baking dish, bake for 10 mins in a 425F/215C pre-heated oven. Remove from oven and layer on the sliced apple cook for a further 12-15 mins until puffed and golden.