0 Heat the oven to 425°F. Halve the squash lengthwise, scoop out the seeds, and peel.
1 Place the squash halves in a baking dish just large enough to hold them side by side. (Alternatively, use a braiser or an oven-safe skillet). Rub all over with 1 tablespoon of the oil and season both sides generously with salt and black pepper. Arrange cut side down and roast until beginning to soften, 15 to 20 minutes (a paring knife should slide in only about 1/4").
2 Meanwhile, whisk together the maple syrup, remaining 2 tablespoons oil, and a pinch of red pepper flakes until combined.
3 Transfer the squash to a cutting board and let cool slightly. Place one half between two chopsticks (these will prevent you from cutting all the way through). Score the squash into thin shingles crosswise, stopping when you reach the chopsticks. Return to the baking dish and repeat with the second half. There are tons of YouTube videos showing this technique if you need a visual!
4 Tuck the sage leaves between a few of the shingles, drizzle with half of the maple syrup mixture, and season again with salt and pepper. Return to the oven and roast, basting with the remaining maple syrup mixture (and any that has pooled in the baking dish) halfway through, until completely tender, 45 to 60 minutes. I like to baste again when there's 10 minutes left on the timer. Be sure to really get it into all the nooks and crannies! Remove any burnt bits with a spoon, if necessary.
5 Top the squash with your desired toppings, such as feta, pistachios, parsley, and dried cranberries. (Just make sure you have something salty to offset the sweet squash.) Serve warm.
