An apple crumble is a British dessert featuring baked apple with a crunchy topping. In the UK, the term "crumble" refers to both a dessert similar to the American apple crisp, which is topped with rolled oats and brown sugar, or a dessert topped with a finer mixture of butter, flour, and brown sugar. In the US, the term only refers to the latter.
It is also popular in the United States and many other English speaking countries.
The crumble topping is made of butter, flour, and brown sugar rolled together so that it resembles breadcrumbs. Care must be taken to balance the correct amount of crumble with the fruit, or else the filling may seep through and spoil this crust. Crumble is traditionally served with custard, but today it is sometimes served with cream or ice cream. Crumbles made from apples, and sometimes other fruits, are also common in Australia, New Zealand and Ireland.