It all comes down to the topping. Crisps and crumbles both have a streusel-like topping made with flour, sugar, butter, and salt. But, the topping for a crisp will usually also contain oats and sometimes nuts, giving it a thicker, crunchier texture than a crumble. Cobblers have a cake or biscuit-like topping with a lot of exposed fruit filling, giving it the appearance of a cobbled road.