Black Flame

You throw a ball of black fire at a creature or object within range. Make a ranged spell attack against the target. On a hit, the target takes 2d8 fire damage and is set alight with blackflame for the duration.
While alight, a creature takes fire damage equal to half of its level or CR (whichever is applicable) at the start of each of its turns. The target or another creature can use its action to put out the fire.
At Higher Levels.
When you cast this spell using a spell slot of 3rd level or higher, the initial damage increases by 1d8 for each slot level above 2nd. When you cast this spell using a spell slot of 5th level or higher, the duration increases to 1 minute.