Dragonfire

A bright streak of flame flashes from your mouth to a point you choose within range and then blooms with a loud roar into an explosion. Each creature in a 40-foot-radius square centered on that point must make a Dexterity saving throw. A target takes 8d6 fire damage on a failed save, or half as much damage on a successful one.

It ignites flammable objects in the area.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 4th.