Butternut Squash Soup with Hazelnut Gremolata

Here is the perfect fall soup. Crispy, buttery croutons add textural contrast to the velvety butternut squash purée, and an Italian-inspired gremolata made with toasted hazelnuts lends a bright, refreshing note. The soup, croutons, and gremolata can all be made up to 2 days in advance (just reheat the soup gently in a saucepan), but wait until just before serving to combine them.