Peel and cut the apples into small pieces, then mix together with the 50g of the brown sugar and cinnamon. Cook in a saucepan over low heat for 10 minutes, stirring occasionally.
Combine the flour, 100g brown sugar and mixed spice in a bowl, then add the butter. Rub together until the mixture comes together like breadcrumbs. Stir in the pecans.
Pour the apple mixture into an ovenproof dish and then top evenly with the crumble topping.
Bake in a preheated 180 C / Gas 4 oven for 35 to 40 minutes until the top is golden and crisp. Serve with vanilla ice cream or custard!
Tip
It's important to use light brown sugar for a richer flavour.