Blue-Frost Blade

You brandish the weapon used in the spell’s casting and make a melee attack with it against one creature within 5 feet of you. On a hit, the target suffers the weapon attack’s normal effects, and you cause restricting frost to form over their body. The target suffers 1d6 cold damage and its speed is reduced by 10 feet until the end of its next turn.

The spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (2d6), and 17th level (2d6).