Bolganone

Choose a spot within range, a circle of fire erupts from the ground with that point at the center and a radius of your choice (up to 20ft). any creatures within 10ft of the ground (including beneath it) in that area must make a constitution saving throw or take 9d6 fire damage, or half as much on a successful saving throw.

At Higher Levels: when you cast this spell with a spell slot of 5th level or higher, the damage increases by 1d6 and the maximum radius increases by 5ft for each level after the 4th.