Heat oven to 350°F. Cut squash in half lengthwise; remove seeds. Cut squash halves crosswise into 1-inch-thick slices. Arrange slices in 13x9-inch (3-quart) glass baking dish; cover with foil.
Bake at 350°F. for 30 to 35 minutes or until almost tender.
Meanwhile, melt butter in small saucepan over medium heat. Stir in brown sugar, syrup and pecans. Cook just until sugar dissolves, stirring constantly.
Remove squash from oven. Spoon pecan mixture over squash. Return to oven; bake an additional 10 to 15 minutes or until squash is tender, spooning pecan mixture occasionally over squash.