Preheat to 350 degrees F
Peel and slice the apples into cubes.
Place the apples in a pan and toss them in with sugar, cinnamon and lemon juice. Simmer on medium-low heat for about between 5 to 10mins minutes until the apples soften slightly.
In a large bowl, mix together the flour, sugar, lemon zest, lemon juice for the topping. Using a pastry cutter or your fingers, gently add in the cold butter until bread crumb texture is formed.
Now pour the apples into a baking dish, and spread it out into an even layer.
Pour the milk over the apples.
Finally, top the apples evenly with the crumble mixture and bake until the apples are bubbly and the topping is golden brown for about 45-50 minutes.
Rotate the container once halfway through cooking.
Serve warm with custard and enjoy.