Prepare the apples by coring, peeling and slicing, and place them in the slow cooker.
4 large Bramley/cooking apples
Make the crumble in the usual way; sift the flour into a bowl, rub in the butter, stir in the sugar and oats. Add the cinnamon.
200 g plain flour (all-purpose flour), 125 g butter, 100 g golden caster sugar, 70 g porridge oats, 1 tsp cinnamon
Tip in the sugar for the fruit over the chopped apple, and give it a stir. Spray the sides of the slow cooker bowl where the crumble will be with some cooking spray or oil, to prevent sticking.
75 g golden caster sugar
Finally, tip the crumble mixture over the fruit and press it down lightly.
Now switch the slow cooker on to high, place a clean tea towel under the lid to stop water dripping onto the crumble, and cook on high for 3 hours.
After two and a half hours, place the lid ajar and cook for another 30 mins to an hour until the crumble firms up and starts to go crispy around the edges.Serve and enjoy!