Blazing Smite

When you hit a creature with a melee weapon attack, a blazing flame erupts from the point of impact. The target and all creatures in a 10-foot cone originating from the target must make a Dexterity saving throw. A creature takes 1d10 fire damage on a failed save, and half as much damage on a successful save.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the extra damage dealt by the attack increases by 1d10 for each slot level above 1st.