Thaw two 13-ounce packages frozen French toast and cut into 1 1/2-inch cubes. Heat oven to 325ºF. Lightly coat a 13-by 9-inch baking dish with cooking spray. Place the toast in the dish. Beat 4 cups milk, one 12-ounce can chocolate syrup, and 2 eggs; pour over the toast. Cover with foil and bake 10 minutes. Remove foil and stir. Bake, uncovered, 20 to 25 minutes longer or until set. Serve warm with canned whipped cream.