Apple and sultana crumble is a classic British dessert that combines sweet and tart apples with juicy sultanas, topped with a crunchy crumble topping. The apples and sultanas are cooked until soft and tender, then topped with a mixture of flour, butter, and sugar. The crumble is baked until golden and crispy, creating a delicious contrast of textures. Serve this warm dessert with a scoop of vanilla ice cream or a dollop of custard for a comforting and satisfying treat.