Can this be made ahead and frozen at any point?
Thanks for asking!!! Balsamic syrup, made by concentrating balsamic vinegar, is a readymade product that's usually on the shelf right near the balsamic. It comes in white and dark, and it's sometimes flavored. The consistency is closer to a loose honey, and it's a bit sweeter than balsamic vinegar, but it has the same flavor. You can make it by simmering balsamic vinegar until syrupy.
Food & Wine - the recipe for Rhubarb Pudding Cake lists balsamic syrup in the ingredient list, but then it isn't mentioned in the directions. Please explain what I should do because I'd like to make this for my husband.