Making thick jam
I'm looking to make a thick jam as a cookie filling,
is this possible using traditional pectin methods
or do I need to go the route of gelatine/cornstarch ?
Cook it down until its as thick as regular jam before adding pectin and it'll set up like fruit paste. Bear in mind that if you bake it open to the heat, it'll set up further in the oven. I use normal jam for thumbprint cookies and never have an issue.
If you prefer to start from scratch and not reduce purchased jam, I think a little more pectin or cooked a degree or two hotter, or both would help.