Warm the butter in the microwave for 15 seconds. Add brown sugar and stir until combined. Add vanilla and milk.
Add blended oats, protein powder, and salt. Stir until combined. Add chocolate chips and stir. If the dough is a little dry, add another splash of milk!
The dough will be a little sticky. Cover and transfer to the fridge for 10 minutes, then scoop into small balls. Eat immediately or store in a sealable container in the fridge!