Step 1

Preheat oven to 450 degrees F. Place squash, shallots, garlic, thyme, rosemary and sage on a large rimmed baking sheet. Drizzle with oil; toss to coat. Spread in an even layer. Roast until very tender, 30 to 35 minutes, stirring halfway through cook time. Remove and discard the thyme and rosemary. Transfer the remaining squash mixture to a blender.

Step 2

Add broth to the blender. Secure lid on the blender, and remove center piece to allow steam to escape. Place a clean towel over opening. Puree until smooth, about 45 seconds. (Use caution when pureeing hot liquids, and puree the squash with the broth in batches if necessary.)

Step 3

Pour the soup into a medium saucepan; stir in vinegar, maple syrup and salt. Bring to a boil over medium-high heat, stirring occasionally. Ladle evenly into 6 bowls; dollop each with 1 1/2 tablespoons crème fraîche. Garnish with thyme leaves, if desired.