Line a baking sheet with parchment paper and set aside for now.
Add the oats, coconut, and walnuts to a food processor and pulse until mixture resembles coarse crumbs.
Add the mashed banana, maple syrup, vanilla, cacao powder, chia seeds, and flaxseed meal. Pulse until everything is mixed together and the mixture can be formed into a ball. If it is too wet, add more oats, ground flaxseed, or cacao powder. If mixture is too dry and crumbly, add small amounts of water until desired consistency is reached.
Remove the blade and use a rubber spatula to fold in the cacao nibs or mini chocolate chips, if using.
Use a small cookie scoop to scoop mixture into 1" balls onto the parchment-lined baking sheet. Use your hands to roll them out until smooth, and then place in the refrigerator to set.
After the energy bites are chilled, transfer them into a sealed container and store them in the refrigerator.
