Ok, found it, Explosive Cascade.
Since the area is one 5' square/level, and it states a continuous path, I see a creative application of the wording to include winding the line of this spell in a loop over the same space more than once, are you asking if you can loop in this manner and therefore if you could deal multiple attacks worth of damage?
The first thing I think of as a precedent to this concept is some of the Tome of Battle Desert Wind, fire-related maneuvers. The Firesnake, a maneuver that makes a winding line of fire, specifically states that you cannot hit an opponent more than once with the attack. It's a level 4 maneuver, instantaneous, reflex-half, supernatural ability and in many ways similar to this spell.
All in all, I'm guessing the answer is No.