Line a 9 inch square cake tin with parchment and preheat the oven to 170c.
Mix the butter, sugar, flour and spices until crumbly and press into the tin.
Bake for 18 minutes.
Meanwhile, make the filling. Add all of the ingredients to a pan and gently cook for about 15-20 minutes until the apples are soft and the sauce thick. Leave to cool.
Make the crumble by rubbing the butter into the flour and sugar. Set aside.
Add the apple topping to the par-baked shortbread and crumble over the topping.
Bake again for 15-18 minutes.
Drizzle with the water icing, slice and enjoy!
