Ultimate Magic Missile

You create a single, powerful, glowing dart of magical force with all the magic you can muster. The dart strikes a creature of your choice that you can see within range. A dart deals 4d8 + 4 Force damage to its target. upon impact, the dart splits into two darts, each dealing half damage of the original. when these darts hit another target, they split off again, each dealing half of the previous darts. The darts of each stage all strike simultaneously, and you can direct them to hit one creature or several.

Using a Higher-Level Spell Slot. The spell creates one more original dart when cast using a 9th level spell slot