You hurl an erratically twisting and spinning flame at a creature you can see within range. The target must make a Dexterity saving throw. On a failure, it takes 1d10 fire damage and is set ablaze, until someone takes an action to douse the flames. A burning creature takes 1d10 fire damage at the start of each of its turns, and the damage dealt by its weapon attacks is halved.
Creatures immune to fire damage are immune to this effect.

At Higher Levels. When you cast the spell with a spell slot of 3rd level or higher, the initial damage increases by 1d10 for each slot level above 2nd.