For the crumble sitr the light brown soft sugar, plain flour and the wholemeal plain flour together in a mixing bowl
Add the butter to the bowl in chunks or cubes, then using your fingers, rub it into the flour and sugar until it resembles breadcrumbs. You can also do this in a food processor if you prefer, or with a fork
Peel, core and chop the apples into small pieces and place in a bowl. Use an apple cutter to do this quickly and avoid the apples browning. Or you can put a squeeze of lemon juice into a bowl of water and add the apple chunks to it as you cut them. Drain them off when you're done
Add the sultanas, light brown soft sugar, cornflour, cinnamon, mixed spice and nutmeg to the apples and stir them all together
Put the apple mix into a baking dish (ideally 32.5 x 19 x 8 cm)
Spread the crumble topping over the fruit and bake it for 45 minutes or until golden and bubbling
Serve warm, or leave to cool fully, cover the dish with cling film and store in the fridge for up to 3 days
Notes
You can use either unsalted butter or a baking spread for the crumble topping.
Mixed spice is a British spice blend containing cinnamon, coriander seed, nutmeg, clove, pimento and ginger. If you can't get hold of it, use a mix of these spices or use a Pumpkin Spice mix instead.
I really recommend using light brown soft sugar if you can, as it gives the crumble a lovely caramel flavour. But if you can't get hold of it, you can use golden caster sugar or regular caster sugar (superfine sugar) instead.
I like to add a bit of wholemeal flour into my crumble mix for texture and goodness, you could replace it with porridge oats, ground almonds, or the same amount of regular plain flour.
Although I provide cup measurements, I highly recommend weighing your ingredients out using digital kitchen scales*. It is the most accurate way to measure ingredients and will ensure the best results. Digital scales are very low cost and can be purchased for around £12 ($16.50) .
For teaspoon (tsp) and tablespoon (tbsp) measurements, please use measuring spoons* and not the type of spoons you eat with. Again this will ensure accuracy and provide the best results.