Clean the inside of the melon of rind and seeds. Cut it into small cubes. Put the melon in a pan and sprinkle with sugar and vinegar.
Put the pan on the stove and stir constantly to prevent sticking. Add the butter, cinnamon and vanilla pod, scrape the pod with a richer flavor.
Allow the jam to boil 15-20 minutes, reduce the heat and boil for another 25 minutes.
The ready, hot melon jam is poured into jars, close them immediately and place upside down to cool.
Store the melon jam in the a dark cool place.