Apple crumble is the easiest apple cake recipe and an all-time favorite dessert. All you can do to make it absolutely perfect is pay attention to the little tricks. Cinnamon apple filling, topped with a soft, crispy, golden topping. You'll love that this apple crumble is not overly sweet and that the filling is syrupy and jammy instead of watery or dry. The smell of this baked good should have already lured you into the kitchen. Now let's get to making the apple crumble.