In a medium mixing bowl, combine the peanut butter, vanilla protein powder, rolled oats, ground flaxseed, mini chocolate chips (or coconut), honey, and chia seeds.
Stir the mixture using a sturdy rubber spatula or wooden spoon until it begins to come together; switch to your hands if needed to fully mix.
Check the dough's consistency. If it is too dry, add water 1 teaspoon at a time until it holds together. If it is too wet or sticky, add a few teaspoons of oats or protein powder until the dough is easy to roll.
Let the mixture sit a few minutes so the oats and protein powder can absorb moisture, then adjust texture if necessary.
Use a 1-tablespoon cookie scoop or a tablespoon to portion the dough, then roll each portion between your palms into a ball. Lightly wet your hands if the dough clings. You should have about 16 balls.
Store the protein balls in the refrigerator or freeze if desired.
