Bring these butter, buttermilk and sugar to a boil in a large pot. It will bubble up a lot so make sure to use a large stock pot.
Once bubbling add soda and vanilla. It will foam up high. Continue boiling and stirring for 1-2 minutes. Take off heat. Let cool and foam will dissolve. Serve immediately over pancakes, french toast, waffles, dutch pancakes, crepes or whatever is your favorite!
Store in airtight container, and re-heat before use.
HOW LONG DOES BUTTERMILK SYRUP LAST?
If you are serving immediately place in a container to pour conveniently from, or let cool to room temperature and store in an air tight container in the refrigerator for 1-2 weeks.