Peel and core apples and cut into small cubes. Place apples in a large saucepan and cover with water. Simmer covered with lid on med-high heat until apples are just tender but not too soft (usually around 5 minutes). Drain apples well and place in a large bowl. Combine sugar and cinnamon and toss through the apples.
For the crumble, combine flour, sugar, oats, coconut, cinnamon and nutmeg in a large bowl until evenly combined. Add melted butter and vanilla essence and mix well using a fork.
Place apple mix evenly in a medium casserole dish. Spread crumble mix over the top of the apples. Bake at 180oC for 30-40 minutes or until crumble topping is slightly browned.