Black Powder Step

You conjure and detonate magical munitions in a space you can see within range, then teleport to switch places with them as they explode. When the munitions appear, and again after they teleport, each creature within a 10-foot Emanation centered on them must make a Dexterity saving throw, taking 3d6 Fire damage on a failure, or half as much damage on a success.

Using a Higher-Level Spell Slot. The damage increases by 1d6 and the range by 30 feet for each spell slot level above 3.