Birch’s empowered strike

“Hit the elbow drop!” - Hara 

Your extremities are covered in luminescent blue shrouds of magical force. once per round, your unarmed strikes do additional force damage equal to your spellcasting ability modifier. And you may use your spellcasting ability in place of strength for your attack rolls. you may make one unarmed strike when you cast this cantrip

At higher levels

this spells additional damage increases to 2x your spellcasting ability modifier when you reach level 5, 3x when you reach level 11. And 4x when you reach 17th level