Baked French Toast

To make the french toast: Spread butter over bottom of heavy large baking pan with 1-inch-high sides. Arrange bread slices in pan. Beat eggs, milk, sugar, syrup, vanilla and salt to blend in large bowl. Pour mixture over bread. Turn bread slices to coat. Cover with plastic and refrigerate overnight. Preheat oven to 400?F. Bake French bread 10 minutes. Turn bread over and continue baking until just golden, about 4 minutes longer. Transfer cooked toast to plates and sprinkle with powdered sugar. Serve immediately, passing Maple-Walnut Syrup separately. To prepare maple syrup: Combine syrup and walnuts in heavy medium saucepan. Bring to simmer. Serve syrup hot. Makes about 3 cups.