How to make
Wash and pit the fruit. Cut them into small pieces.
Peel and slice the apple.
Mix the fruit, put them in a large enough pot and sprinkle them with sugar. Mix well and wait about an hour or two, until the fruit release their juice.
Put the pot on low heat and boil the jam for about 2 hours, by stirring occasionally.
Turn off the heat and leave the marmalade cool.
Puree the cooled marmalade. Put the pot back on moderate heat and boil for about 15 minutes, this time stirring constantly, so that it doesn't stick to the bottom.
Five minutes before removing it from the heat, pour the juice of one lemon.
Remove the finished yellow plum marmalade and flavor it with vanilla.
Pour the yellow plum marmalade into dry, warmed jars and seal them immediately.
Turn them over with the lids facing down, until they cool down.
