Preheat oven to 400°.
Arrange squash in a single layer on a foil-lined baking sheet coated with cooking spray. Bake at 400° for 45 minutes or until tender.
Melt butter in a Dutch oven over medium-high heat. Add apple, onion, celery, and bay leaf; sauté 10 minutes. Stir in curry powder and garlic; cook 1 minute, stirring constantly. Add squash, broth, and salt; stir well.
Reduce heat to medium-low; simmer, uncovered, 30 minutes. Discard bay leaf. Partially mash mixture with a potato masher until thick and chunky; stir well with a spoon. Top each serving with cheese.