1 1/2 cup water
3 3/4 cup sugar (I used a mix of brown sugar and white sugar but anything that is pure sugar is fine)
1 teaspoon Vanilla Extract
a little less than 1 cup of Vanilla infused Balsamic Vinegar (if you don't have a store that carries this, try apple cider vinegar instead and increase the amount of Vanilla Extract to taste)
I put everything in the sauce pot and brought it to a boil. I then stirred it, while it was boiling, for a couple of minutes, only to turn it down to low and leave it for about 10 minutes. I then took it off the stove and let it cool.
Once it was cool, I put about a tablespoon in my cup and poured sparkling water over it (from my Sodastream). I was worried it would be too bitter but it's surprisingly light and gives just the right amount of flavor for a soda. Since sugar isn't exactly expensive (you can buy a box at the dollar store), this is a pretty easy, cheap soda flavoring syrup recipe.