Bombardment

You create three small beads of fire and hurl them at targets within range. You can hurl them at one target or several. You also create one large ball of flame and launch it at the first target you hit. You make a ranged spell attack for each bead of fire. On a hit, the target takes 3d6 fire damage.
After all the beads of fire have been hurled the ball of flame detonates on the first target you hit, each creature within 20 feet of the target must make a Dexterity saving throw. A creature takes 6d6 fire damage on a failed save, or half as much on a successful one. You may add 1d6 fire damage to the ball of flame for every bead of fire that hit.

At Higher Levels. If you cast this spell using a spell slot of 7th level or higher, the amount of beads increases by one for each slot above 6th.