In a large bowl, mix oats, protein powder, chia seeds, and flaxseed until evenly combined to ensure balanced texture and nutrition.
Add peanut butter, honey, vanilla extract, and salt, then mix thoroughly until a sticky dough forms that holds together.
Adjust consistency by adding small amounts of liquid if too dry or oats if too sticky, ensuring the mixture is easy to shape.
Fold in optional ingredients like chocolate chips or nuts to enhance flavor and texture.
Scoop and roll into evenly sized balls using your hands or a scoop for consistency.
Chill in the refrigerator for at least 20 minutes until firm and ready to serve.