Divine Flame

You create an arrow made of intense flame between your fingers and launch it at a target. If the target has been hit previously by the Cleave or Dismantle spells, the arrow erupts into an all-consuming sphere of fire, scorching all creatures within a 15-foot radius centered at the initial target. Each affected creature takes  8d8 Fire damage on a failed save or half as much on a successful one.

Flammable objects hit by the spell that aren’t being worn or carried start burning.

Using A Higher-Level Spell Slot: The damage increases by 1d8 for each spell slot above level 5.