These generously sized cookies are soft and cake-like. Spiced with cinnamon and ground ginger and made with just 4 tablespoons of butter, their flavor is mostly about the bittersweet, subtly smoky notes of molasses. Use either mild or “robust” (or “full”) molasses, but avoid blackstrap molasses; its potent flavor will overpower the spices and make the cookies taste harsh and bitter. A browned butter icing gives the cookies a rich, elegant finish. Refrigerate leftovers in an airtight container for up to three days.