Of course, if you want to OP power game the dragonborn sorc class, you can always take:
Ancient Soul
Hurl Breath
Example:
Minor action, fire breath as a area burst 2, hitting yourself with one of the squares.
Assuming you hit (yourself), apply damage (somewhat high however, due to no resistance), and recharge breath.
Standard action - repeat.
Move action - repeat.
Action point - repeat.
This of course assumes you can hit yourself repeatedly with your breath. Easy enough to build around, ie. hit against reflex.