Preheat oven to 425 degree F. Lightly grease a 2-quart baking dish; set aside. Peel the squash. Slice to 1/4-inch thickness. Remove seeds from slices and halve large slices. Arrange slices in a 15x10x1-inch baking pan. Brush both sides lightly with olive oil. Season with salt and pepper. Bake, uncovered, 20 minutes. Remove. Increase oven temperature to 475 degree F.

Meanwhile in a 4- to 6-quart Dutch oven cook the spinach in lightly salted boiling water, half at a time, for 1 minute or until wilted. Drain and cool slightly; squeeze out excess liquid. Coarsely chop the spinach; set aside. In a medium saucepan combine half-and-half and cornstarch; cook and stir until thickened and bubbly. Stir in spinach; spread mixture in bottom of prepared dish. Arrange squash over spinach mixture.

In a small bowl stir together Parmesan cheese and creme fraiche. Spread mixture over squash in dish. Bake, uncovered, 10 to 15 minutes or until squash is tender and topping is lightly browned. Season to taste with salt and pepper, if desired. Makes 8 servings.

To make your own creme fraiche, in small bowl stir together 1/4 cup whipping cream (not ultrapasteurized) and 1/4 cup dairy sour cream. Cover with plastic wrap. Let stand at room temperature for 2 to 5 hours or until mixture thickens. When thickened, cover and chill in the refrigerator until serving time or up to 48 hours. Stir before serving.