Preheat the oven to 400 degrees. Line a baking sheet pan with foil. Spray the foil with nonstick food spray.
Place the winter squash cubes in a mixing bowl. Toss with 2 tablespoons of the maple syrup and one tablespoon olive oil. Roast in the preheated oven until the squash is cooked through, but still slightly firm, about 15 minutes.
Cook the bacon. Heat a skillet on medium high heat, add the bacon, and fry until crisp. Remove the bacon and drain on a paper towel, keeping about 1 tablespoon of bacon drippings in the pan.
Add the red onion and garlic and sauté for several minutes.
Add the roasted squash and the cooked bacon back into the pan. Add the remaining maple syrup. Gently toss to combine and cook over medium heat for one minute. Add the chopped kale and the fresh sage. Toss gently to combine.
Cover and cook for several minutes until the kale is just wilted. Season to taste with salt and white pepper.