Preheat oven to 425F, with rack on upper middle position.
On a large baking sheet with rims, toss together all ingredients until vegetables are well coated with seasoning and oil.
Roast about 30 minutes, or until nicely browned. (Oven temps vary, so just watch and remove when the vegetables are tender and browned.) If needed, add more salt and pepper to taste.
Notes
Cut evenly: Keep the squash cubes about 1 inch and halve the sprouts (quarter any big ones) so everything finishes at the same time.
Don’t crowd the pan: Use a single layer with the sprouts cut side down. If your pan is small, split everything between two pans so the veggies roast instead of steam.
Fresh only: Frozen sprouts or squash release too much water and won’t caramelize.
Ovens vary: Start checking at 25 minutes. You want them fork-tender with deep golden edges.
Make ahead: Cut the squash and trim the sprouts up to 3 days ahead. Store them separately in the fridge.
Leftovers: Refrigerate in an airtight container for up to 4 days. Reheat at 400°F for 5 to 8 minutes in the oven or air fryer.