You rapidly assemble, prime, and throw an alchemically catalysed explosive, targeting either a creature or an unoccupied space of your choice within range. If targeting a creature, make a ranged spell attack against the target. On a hit, the target takes 1d6 fire damage as the bomb explodes, and all creatures within 5 ft of the target take fire damage equal to your spellcasting ability modifier.
If you target an unoccupied space, all creature within 5 ft of the space must make a Dex saving throw, or take fire damage equal to your spellcasting ability modifier, as though they were secondary targets of the bomb.
The bomb's potency increases when you reach higher levels. At 5th level, the main target takes an extra 1d6 fire damage, and the fire damage to secondary targets increases by 1d6 + spellcasting ability modifier. Both damage rolls increase by 1d6 at 11th level and at 17th level.