Chilling Smite

The next time you hit a creature with a melee weapon attack during the spell's duration, your weapon becomes coated with biting frost, and the attack deals an extra 1d6 cold damage to the target and reduces its speed by 10 feet until the spell ends.

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