Cut the apples into rough pieces and place them in a pot with sea buckthorn, sugar, water, and vanilla bean.
Give the mixture a quick boil, then lower the temperature so the jam can simmer until done.
After 30 minutes on the stove, strain the now-cooked fruit through a fine-mesh sieve to remove skins and seeds from the finished jam.
Return the strained mixture to the pot, give it a quick boil, and adjust the taste with sugar and vanilla.
Pour the jam into clean, sterilized jars, and seal them immediately.
The shelf life of sealed jars stored in a cool, dark place is about two months, while opened jars will stay fresh for a couple of weeks in the refrigerator.