Trim crust from bread using a serrated knife, and discard crust. Cut bread into 1-inch cubes. Arrange bread cubes in a single layer on a baking sheet. Bake at 350° for 12 minutes, or until toasted.
Combine skim milk, brown sugar, bourbon, vanilla extract, and eggs in a bowl; stir well. Add bread cubes and raisins; toss gently. Cover and chill 45 minutes.
Spoon mixture into a 9-inch square baking dish coated with cooking spray. Cover and bake at 350° for 20 minutes. Uncover and bake an additional 10 minutes or until pudding is set.
Pour caramel sauce a small, microwave-safe bowl. Microwave for 30 seconds, or until warm. Serve with bread pudding.