Preheat oven to 180C/160C fan-forced. Grease a 5cm deep, 24cm round pie dish.
Use a whisk to whisk the flour, sugar, coconut, eggs, vanilla and butter in a large bowl. Gradually add the milk, whisking constantly, until combined.
Place the apple slices over the base of the prepared dish. Pour over egg mixture.
Bake the pie for 1 hour or until set. Set aside to cool before serving.