Peel the apples, cut into slices and lined them in 9 x13 baking dish.
In a large bowl, combine the butter and flour, add the lemon juice, milk and vanilla extract, mix well.
Then add brown sugar, cinnamon and a little salt.
Pour this mixture over the apples and make a crumb topping.
In a medium sized bowl combine the flour, oats, brown sugar, baking powder,cinnamon and add the diced butter, which you should crumble with fork.
Sprinkle this over the apples and bake it in preheated oven (375 F) for about 35 minutes, until golden brown.
Cool it before serving.
Serve it with a scoop of ice cream and caramel sauce.