Erupting Earth

Casting Time: 1 action
Range: 120 feet
Duration: Instantaneous
Churned earth and stone erupts in a 20-foot cube. Creatures takes 3d12 bludgeoning damage on a failed Dexterity saving throw, or half as much damage on a successful one. Ground in that area becomes difficult terrain until cleared. Hand clearing terrain 5ft/min.
Damage increases by 1d12 for each slot level above 3rd