Preheat oven to 180 C (350F)Make the crumble: in a food processor or blender, blend half the oats into flour. Place the oat flour with the rest of the oats in a bowl, along with the sugar, spices and salt. Whisk to combine. Add the cold cubed butter and using the tips of you fingers, rub the butter into the mixture until it is well dispersed and the mixture is crumbly with small clumps (refer to photos). Mix through the chopped nuts. Cover the bowl and place in the freezer while you prepare the apples.Butter a baking dish or pie dish (the one I used is 22cm x 15cm and 5cm deep/ 9â€x6†and 2†deep) and set aside.Peel, core and chop your apples, place them in a bowl. Add the lemon juice, sugar/honey and spices and mix well. Pour this mixture into your prepared baking dish and spread it out evenly.Take the crumble mixture out of the freezer and spread it evenly onto the apple mixture. Bake the apple crumble for 45-60 minutes, until the top is golden brown and the apples are sizzling and bubbling. Serve warm with some yoghurt, creme fraiche, custard or ice cream.