Place Maple syrup in a small pan, bring to a boil, reduce heat to medium and allow syrup to reduce by about half. In a small bowl, whisk together the reduced maple syrup with the vinegar, whisk in the Dijon mustard, then whisk in the oil until mixture is emulsified. Season with salt and pepper to taste.
Method to prepare the salad:
Washed mix greens and spinach leaves and set aside. Remove skin and seeds of Butternut squash and into cubes/dice (about 3/4-inch). Slices of bacon, sliced crosswise into thin strips and fried until just crisp, drained. Spray some oil on the pan and roast pecans. Place diced butternut squash on rimmed baking sheet, toss with a tablespoon olive oil to coat, then sprinkle lightly with kosher salt and freshly ground pepper. Roast in hot oven turning pieces once or twice until just tender but not mushy. Remove from oven and allow to cool slightly. Arrange mix green and spinach leaves in salad bowl and add roasted butternut squash, crispy bacon and pecans. Drizzle with Maple Vinaigrette. Add salt and pepper before serving.