This roasted squash and spinach salad is a bright, fresh way to enjoy the flavors of Fall. For the best flavor and presentation, it should be served immediately after assembling, as the spinach leaves will lightly wilt from the roasted squash slices and warm vinaigrette. I like to serve the salad lightly-dressed to allow the flavors of the squash and spinach to shine through, but if you prefer more dressing, the vinaigrette is easily doubled.