Barkus's Molten Bolt

A bolt you raise in the air heats up until the tip starts to melt, and launches towards a target in range. Make a ranged spell attack against the target. On a hit, the target takes 4d4 fire damage, and the target has disadvantage on attack rolls and ability checks until the end of its next turn. On a miss, the bolt splashes the target with molten metal for half as much damage and the target does not suffer any disadvantage

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage (both initial and later) increases by 2d4 for each slot level above 2nd.