Vampiric Smite

The next time you hit a creature with a weapon, unarmed, or natural attack before this spell ends, your weapon, fist, or natural weapon gleams with dark energy as you strike. The attack deals an extra 1d6 necrotic damage to the target, you heal for the amount of damage dealt by this spell and prevent the target from healing until the end of your next turn. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the extra damage increases by 1d6 for each slot level above 2nd.