Arrange squash in a single layer on a jelly-roll pan coated with cooking spray. Coat squash with cooking spray; sprinkle evenly with 1/4 teaspoon salt and 1/4 teaspoon pepper.
Bake at 400 for 30 minutes or until squash is tender and lightly browned, stirring after 15 minutes.
Cook bacon in a small nonstick skillet over medium-high heat until crisp.
Remove bacon from pan, reserving 1 teaspoon drippings in pan. Crumble bacon; set aside.
Add shallot to drippings in pan; saut 1 minute.
Add shallot and bacon to vinegar mixture, stirring with a whisk.
Place salad greens in a large bowl.
Drizzle vinegar mixture over greens; toss gently to coat. Arrange about 1 1/3 cups salad on each of 6 plates. Top each serving with 2/3 cup squash and 1 1/2 teaspoons pumpkinseed kernels.