Spellcaster Signature Spell

Your mastery over your arts has granted you the ability to cast a spell from a list three levels lower than your current maximum level and make it your signature spell. If you are able to cast 4th level spells, select a spell from your known 1st level spells. This spell can be cast a number of times per rest equal to your Constitution modifier.  All requirements to cast the spell must be meet each time it is spent.

This feat can be taken multiple times, to give the ability to have multiple signature spells.