Are there Non vegan substitutes?

Agree with recipe writer Amg not to rejig her recipe with common [not vegan] ingredients.
But for other reasons.
Because it's often complicated and takes more than one try.
If you like the main flavors, there are many other tried and true recipes out there for raspberry and (white) chocolate tart. BBC, allrecipes etc.

I don't recommend trying to substitute non vegan ingredients here. The cacao butter is a large part of the recipe structure (and deliciousness). Besides this and the agar the other ingredients are pretty common and used in a lot of baking recipes so you won't be stuck with them. Check out Navitas cacao butter--you can get it in most health food stores (and wholefoods) and you'll use the whole package.