Place sugar and pears in a large frying pan. Heat and stir from time to time.
This will take some time.
When the water from the fruit evaporites and it starts to caramelize, stir so that the sugar does not burn. When the color gets to dark gold, pour in the water and let it cook until again all the water evaporates.
Take the pan off the heat and immediately add the butter, stir and add the salt and vanilla.