Measure out all your ingredients first
Combine the flour, brown sugar, salt and cinnamon togethor
Rub in the flour mixture with the butter. Cut into cubes and ensure it is cold before you begin
Prebake in the oven at 180°C for around 20 minutes tossing halfway through until the crumble gets golden at the edges
Peel and core all your apples
Roughly chop, around 1 inch in size and place in a bowl with the juice of half a lemon
Toss the apples thoroughly with the brown sugar, salt, cinnamon and vanilla
Place the apples into the cast iron skillet then top with the crumble topping
Bake in a preheated oven at 180°C until golden and the fruit is bubbling. If the topping starts to get too dark, tent with tinfoil