The Fire-Eater's Magic Breath

You eat a fire roasted hot pepper and imbue yourself with the power to spew magical energy from your mouth, provided you have one. Choose acid, cold, fire, lightning, or poison.  AS PART OF THE SAME ACTION IN WHICH THE SPELL WAS CAST, you exhale energy of the chosen type in a 5-ft by 15-ft line.  Each creature in that line must make a Dexterity saving throw, taking 1d8 damage of the chosen type on a failed save, or no damage on a successful saving throw.

At higher level:  

When you cast this spell using a spell slot of 1st level or higher, the damage increases by 1d8 for each slot level above the base Cantrip (level 0) level.