COMBINE sugar, butter, peanut butter and corn syrup in a small saucepan.
COOK over medium heat until smooth and thickened, stir constantly.
COAT a 13 x 9 x 2-inch baking dish with cooking spray. Pour peanut butter mixture into the dish. Fit bread slices tightly into the dish, trimming if necessary.
COMBINE eggs, milk, vanilla and salt in a medium bowl whisking together well. Pour egg mixture over bread. Cover and refrigerate for 8 hours.
BAKE uncovered at 350°F for 45 minutes or until lightly browned. Slice into sections and serve upside down. Garnish with whipped cream or whipped butter.