Peel mangoes, cup the meat off the pit and dice it. Add mango meat to a small pot.
Add sugar, vanilla extract and water. Stir to mix.
Bring to simmer over medium heat and turn the heat down to medium-low to low. Cover, leaving a crack for the steam to escape, and cook for about 30 minutes. Stir occasionally.
Once it's cooked, strain through a fine strainer. Press gently on some of the meat to get juices out.
Store syrup in a glass jar with a lid.
You can keep mango "jam" in the separate jar but use it quicker, it won't keep as long as syrup.
Notes
Disclaimer: Nutrition information shown is not guaranteed to be 100% accurate as most ingredients and brands have a slight variation.