Aganazzar's Minor Explosion

With a snap of your fingers the ground beneath your enemies explodes. Each creature in a 10-foot cube must make a Dexterity saving throw. A target takes 3d8 fire damage on a failed save, or half as much damage on a success.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 3rd. If the spell uses a slot of 5th level or higher the size of the explosion also grows into a 20-foot cube if the caster so wishes.