Cadin's Thorn Ballista

You wave your hands, throwing a violent barrage of razor-sharp thorns at your foes. Choose two targets, and make a spell attack roll. Upon a hit, each target takes 2d8 Piercing damage, and either has their speed reduced to 0, or cannot take reactions until the start of their next turn.

Using a Higher-Level Spell Slot. The damage increases by 1d8 for each spell slot level above 1, and you can target an additional creature for each additional spell slot level above 1.