Draconic Breath( Complete Arcane, p. 77)
You can convert your arcane spells into a breath weapon.
Draconic Heritage (CAr) ,
As a standard action, you can change arcane spell energy into a breath weapon of your draconic heritage energy type. The breath weapon is a 30-foot cone (fire or cold) or a 60-foot line (acid or electricity) that deals 2d6 points of damage per level of the spell that you expended to create the effect. Any creature in the area can make a Reflex save (DC 10 + level of the spell used + your Cha modifier) for half damage. This is a supernatural ability.