Position racks in the upper and lower thirds of your oven and preheat the oven to 400 degrees F. Coat two baking sheets with nonstick spray.
Place the squash in a large bowl. Drizzle with the olive oil and Maple Mayhem, then sprinkle the salt, cinnamon, and pepper over the top. Toss to coat, then divide between the two baking sheets, thowing out any excess liquid left in the bottom of the bowl. Spread the cubes in a single layer on the baking sheets, do not overlap.
Put the pans in the upper and lower thirds of your oven and bake for 15 minutes. Remove them from the oven, turn the squash cubes with a spatula, then putt hem back in the oven, switching the pans’ positions on the upper and lower racks. If you are using dried rosemary sprinkle it over the top now. Continue baking until the squash is tender, about 10 to 15 additional minutes.
Remove from the oven and if you are using fresh chopped rosemary sprinkle it over the top. Serve warm.