Surf-Door-Ed

You "magically" kick a door off its hinges and infuse it with latent energy. You may hop on top of the door prior to the latent energy taking effect. The door begins to hover 3ft. off the ground and launches itself in a 60ft. long, 5ft. wide line in a direction of your choice. Each creature in the Line makes a Dexterity saving throw, taking 5d6 Bludgeoning damage and knocked prone on a failed save or half as much damage on a successful one. You may hop off the door at any point during the doors travel, landing safely.

Using a Higher-Level Spell Slot. The damage increases by 1d6 for each spell slot level above 3.