Searing Smite

Casting time: 1 Bonus action —Range: Self
Components: V
Duration: up to 1 min. + Concentration
One time on hit with a melee weapon, the attack deals an extra 1 d6 fire dmg and sets the target ablaze.
At the start of each of its turns until the spell ends, it must make a Constitution saving
throw. On a fail it takes 1 d6 fire damage.

At higher levels: +1 D6 on initial hit per spell slot