Heat the oven to 450ºF.

• In a small bowl, combine the currants with the cinnamon vinaigrette and let plump, stirring once or twice.
• Cut the delicata squash in half lengthwise, and scoop out the seeds. Cut the squash crosswise into ¼-inch-thick half-moons.
• Trim the root ends from the Brussels sprouts; cut the Brussels sprouts into quarters.
• Peel and thinly slice the shallots.
• Strip the thyme leaves from the stems.

In a large bowl, combine the Brussels sprouts with half the shallots, half the thyme, and 1 tablespoon oil. Toss well to coat, and season with salt and pepper.
In a second large bowl, combine the delicata squash with the remaining shallots and thyme and 1 tablespoon oil. Toss well to coat, then season with salt and pepper.
On a sheet pan, spread the Brussels sprouts, cut side down, in an even layer; on a second sheet pan, spread the delicata squash mixture in an even layer.
Roast the vegetables in the oven, rotating the pans halfway, until the Brussels sprouts are browned, crispy, and tender, and the squash is lightly browned and soft, 25 to 30 minutes. While the vegetables roast, prepare the hazelnuts.

• Coarsely chop the hazelnuts.

In a large bowl or serving dish, combine the roasted Brussels sprouts and squash with the hazelnuts, currants, and cinnamon vinaigrette. Mix well to combine, then season to taste with more salt and pepper, if needed.

Serve the Brussels sprouts and squash mixture hot or at room temperature, straight from the serving dish or spooned onto individual plates.