For the rhubarb-cranberry jelly, first clean the rhubarb, remove the threads and cut into 1 1/2 cm slices. Mix in a saucepan with the sugar and leave to infuse. Add the red wine, bring to the boil. Cook until firm to the bite.
Mix the cake jelly with a little water and add. Bring to the boil once. Stir the cranberries into the rhubarb-cranberry jelly.