The material below is Open Game Content from a 3PP Source
Greater Spell Specialization
You can sacrifice a prepared spell in order to spontaneously cast your specialized spell.
Prerequisites: Int 13, Spell Focus, Spell Specialization, able to prepare 5th-level spells.
Benefit: By sacrificing a prepared spell of the same or higher level than your specialized spell, you may spontaneously cast your specialized spell. The specialized spell is treated as its normal level, regardless of the spell slot used to cast it. You may add a metamagic feat to the spell by increasing the spell slot and casting time, just like a cleric spontaneously casting a cure or inflict spell with a metamagic feat.