For a softer, cookie-dough texture, pulse oats in a food processor 3–5 times. Skip this if you like more chew.
In a large bowl, combine oats, ground flaxseed, chia seeds, shredded coconut, and a pinch of salt. Stir well.
In a separate bowl, whisk peanut butter, honey/maple, vanilla, and 2 tablespoons milk until glossy.
Pour wet into dry. Mix with a sturdy spatula. If using protein powder or cocoa, add now. If the mixture is crumbly, add the remaining milk 1 teaspoon at a time.
Add dark chocolate chips (and hemp hearts if using). Don't overmix; just enough to distribute.
Pop the bowl into the fridge for 10 minutes. This makes rolling easier and reduces stickiness.
Scoop about 1 tablespoon per ball and roll between your palms. You should get 18–22 balls depending on size.
Place on a parchment-lined sheet and refrigerate 20–30 minutes to firm up.
Enjoy straight from the fridge or let them sit 5 minutes for a softer bite.