Start by toasting the walnuts. Spread on a baking sheet and toast at 350 degrees F for 6-8 minutes or until the nuts are fragrant and nicely browned.
Meanwhile, soften the dates in warm water for 5 minutes so they will be easier to blend.
When the nuts are cooled, remove the dates from the water and add them to the bowl of a food processor (the reserved soaking water can be used later if your mixture is too dry). *See notes if using a blender.
Add the remaining ingredients, minus the sesame seeds, to the food processor and pulse to break down the nuts and chickpeas. Then blend the dough until it comes together and starts to form a ball in the food processor. You may have to stop your machine periodically to scrape the sides and ensure even blending. You should be able to pinch the dough between your fingers and have it stick together. *If the dough is too dry, add little splashes of the water the dates soaked in to help it blend (or use extra maple syrup or tahini if desired). Too much liquid will make the dough too sticky and difficult to handle so go slow. *If your dough is too sticky, add more oats to soak up some of the moisture.
Scoop tablespoons of the dough and roll the dough between your palms to create a ball. Roll the ball in toasted sesame seeds for a crunchy topping and more sesame taste if desired. Continue with the remaining dough. *See notes for instructions on how to toast the seeds.
Store finished protein balls in the fridge or freezer in an airtight container. These will last well in the fridge for up to 1 week and 1-2 months in the freezer.