Wash and core the Kriecherl well. Depending on the variety/size, this can be done well with a cherry pitter, for example, or alternatively cut open with a knife and remove the pit.
Cut the fruit in half, mix with the jelling sugar and leave to infuse for a few hours. Then bring to the boil once and boil for about 5 minutes until bubbly.
Blend coarsely with a hand blender. Pour into prepared jars while still hot.