x2_pc_craft
but this spell-related craft has no failure chance by default
my patch greatly enhances it tho - allows to setup one extra component for each pell in each craft (by default its available only for scroll scribing), also allows to setup specific products for each spell and craft which means that you can create a blueprints for each spell with different name, apearance, caster level even different spell if you wish (aka brewing invisibility spell creates improved invis potion).
IN 1.72 beta you can raise the spell level limits via variable too, while this is easy to do for a scripter, it still enables to do that on a player basis not only globally.
Anyway, I dont like this craft much, it favors spellcasters who are already favored in game in combat etc.