Place nut butter, milk, and chocolate chips in a medium sized heavy saucepan. Cook over low heat until chips melt. Stir well to incorporate ingredients.
Add rolled oats. Remove from heat and stir to coat oats well.
Using a spoon, drop 8 ball-shaped portions of the mixture on a wax paper or parchment-lined baking sheet. Refrigerate for 20-30 minutes to set before serving.