These crinkly, fudgy chocolate nut cookies come from Sweet: Desserts from London’s Ottolenghi. Mashed banana added to the dough not only adds a faintly tropical flavor, but helps keep the slightly underbaked cookies extra soft and moist, while a touch of cinnamon and chopped pecans add warm, nutty notes. These are rather fragile and don’t hold up much more than a day after baking, but they’re so delicious you’ll have no trouble eating the whole batch before then. Since this is a soft, sticky dough, it needs to be chilled twice, for 3 hours total; be sure to plan ahead to allow enough time. You can refrigerate the balls of prepared dough for up to 2 days, or even freeze them up to 3 months. If baking from frozen, add an extra minute of cooking time.