Wash and stone the cherries. Peel the bananas. Scrape out the vanilla pods.
Weigh the cherries and bananas and then prepare the same amount of the preserving sugar 1: 1.
Use the hand blender to chop the cherries and bananas in a saucepan and bring to the boil with the preserving sugar. Add the vanilla sugar, lemon juice and pulp of the vanilla pods. Stir constantly so that nothing burns. Let the mixture simmer for about 4 minutes.
If you like, you can do a so-called gelling test, then I took it off the stove and poured it into the freshly rinsed glasses. Turn the lids on the jars and then turn the jars upside down. The best then is to write on the glasses.