In a large mixing bowl, combine the rolled oats and protein powder (if using).
Add the nut butter and honey (or maple syrup) to the bowl.
Stir the mixture until well combined and sticky.
Fold in the chocolate chips or dried fruit.
Add chia seeds or flaxseeds and vanilla extract.
Mix thoroughly until all ingredients are evenly distributed.
Using your hands, shape the mixture into small balls about 1 inch in diameter.
Place the formed balls on a parchment-lined tray.
Refrigerate for at least 30 minutes to firm up.
Once set, store them in an airtight container in the fridge.