Cursed Fire Bolt

The green cursed flame gives off an extraordinary heat, and you can feel your hands heating up instantly just from the aura it gives off.

You hurl a mote of cursed fire at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 1d12 fire damage. If the spell hits a flammable target that isn't being worn or held, it ignites into cursed flame.  If the spell hits a flammable object that is being held or worn, target must succeed on a DC 13 Constitution saving throw or the item will ignite into cursed flame.  At the start of someone's turn if they are in contact with any cursed flame, they will take 2d4 Fire damage.

When casting this spell, you must succeed on a Intelligence (Arcana) saving throw or take 1d4 +2 Fire damage.  You take half as much on a successful saving throw. 

This spell's damage increases by 1d12 when you reach 5th level (2d12), 11th level (3d12), and 17th level (4d12).