Rimesworn Blade

Ice can be sharper than steel, and splinters like a sap-filled tree in winter cold clutches.
The first time you take the Attack action during your turn, you can cast this spell to infuse your weapon with chilling cold and coat the exterior with brittle ice. The first time you hit with this weapon, the target takes an additional 1d8 cold damage, shattering the ice on your weapon. The target and creatures within 10 feet of the target other than you must make a Dexterity saving throw. If they fail, they take 1d8 piercing damage.

At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, either the cold or piercing damage (your choice) increases by 1d8 per slot level above 1st.