Clash of Glaciers

You conjure icy boulders that crush creatures in a line 100 feet long. Each creature in the area takes 5d6 bludgeoning damage plus 5d6 cold damage, or half the damage with a successful Dexterity saving throw.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the damage increases by 1d6 for each slot level above 5th. You decide whether each extra die deals bludgeoning or cold damage.