MOB's Apple Crumble
Heat your oven to 200°C/400°F.
Make your filling. Peel and core your apples, then dice into 2cm chunks. Place 3/4 of your apples into a medium sized saucepan along with your sugar, the juice from your lemon and your water. Bring to a simmer over a medium heat, then cook for 15 mins until breaking down and turning nice and saucy. Add your remaining apples and stir to combine - these will hold their shape when the crumble bakes to give you juicy apple chunks. Set aside.
Dice your butter into 1/2cm chunks. Pour your flour, cinnamon and nutmeg into a large bowl, then add your butter and rub through with your fingertips until your butter has all broken down and coated your flour - this mixture should resemble fine yellow breadcrumbs. Add your oats, soft brown sugar and demerara sugar (reserving 2 tbsp for later), then continue to rub in until your mixture resembles small pebbles. Pop your bowl in the fridge to rest for 15 mins - this will ensure it stays biscuity and crisp when baked.
Transfer your apple mixture to a pie dish, then top with your crumble mixture. Sprinkle with your remaining demerara sugar.
Bake for 25-30 mins until you have a golden and crisp top. Serve with a big scoop of vanilla ice cream and dig in.