Preheat oven to 400°F (200°C).
Line a baking sheet with parchment paper.
Cut the spaghetti squash in half lengthwise and scoop out the seeds.
Drizzle 1 tablespoon of olive oil over the cut sides and sprinkle lightly with salt and pepper.
Place the squash halves cut side down on the prepared baking sheet.
Roast for 35 to 40 minutes, or until the flesh is tender and strands separate easily with a fork.
While the squash roasts, heat the remaining 1 tablespoon of olive oil in a small skillet over medium heat.
Add the sage leaves in a single layer and fry for 1 to 2 minutes, or until crisp.
Transfer the sage to a paper towel–lined plate and set aside.
In the same skillet, melt the butter over medium heat until it starts to foam and turn golden, about 3 minutes.
Reduce heat to low and stir in the maple syrup.
Scrape the roasted squash strands into a large bowl using a fork.
Pour the warm maple-butter mixture over the strands and toss gently to coat.
Season with the remaining salt and pepper.
Top with the crispy sage leaves before serving.
Serve warm as a side dish or light main course.