Slowly sift the powdered sugar into the melting butter. Simmer until fully combined, and then add the bourbon and vanilla. Continue to simmer for a moment more to cook off the alcohol taste.
Pour over buns hot, or let cool to room temperature and use as a spreadable frosting.
This recipe was provided by a chef, restaurant or culinary professional and may have been scaled down from a bulk recipe. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.