Burning Brand

You brand a sigil into the flesh of a creature in range that allows you to empower your attacks with fire.  Creatures branded by this spell take 1d6 fire damage whenever you hit them with an attack.  Any creature branded with this spell loses any resistance to fire that they had, in addition any creature with immunity to fire instead takes half damage. 

At Higher Levels. When you cast this spell using a spell slot of 3rd or 4th level, you deal an additional 1d6 fire damage on each attack(2d6 total). When you use a spell slot of 5th level or higher, you deal an additional 2d6 fire damage on each attack(3d6 total).