Start this recipe by preparing the fillings. Heat the butter in a large pan and add in the diced apples. Cook gently for a few minutes, then add in the sugar, cinnamon and water and continue to cook for 4 minutes. When the apples are softened, remove off the heat and stir in the cold custard. Next, prepare the almond filling by mixing together all the ingredients to create a soft paste. Put the fillings aside. Lay a filo pastry sheet out on your work surface and brush lightly with melted butter. Add another filo sheet ontop and repeat the process. Next, ¼ of the way into the middle, spread over a tbsp of the almond filling, then 2 tbsp of the cooked apple filling. Roll up like a spring roll (sides in first then roll up) and place onto a greased baking sheet. Repeat the process with all the remaining ingredients. Finally before you bake, brush the filo strudels with a little more butter and sprinkle over the flaked almonds. Bake the oven at 200`c for 20-25 minutes, or until golden brown and cooked through. Serve either hot or cold dusted with icing sugar.