Add oats, ground flaxseed, chia seeds, and salt to the bowl of a food processor or blender.
Pulse 10-15 times until some oats are finely broken, leaving a mix of textures.
Stir in the protein powder directly into the dry mixture.
Transfer the mixture into a large bowl and add peanut butter, honey, and vanilla extract.
Mix thoroughly using a wooden spoon or clean hands until well combined.
If the mixture feels too dry, add water ½ tablespoon at a time until it clumps together easily.
Fold in candy-coated chocolate pieces and mini chocolate chips.
Portion out 2 tablespoons of dough per ball (about 25-28g) and roll into smooth, even spheres. Slightly damp hands prevent sticking.
Place balls in a covered container with parchment paper between layers to avoid sticking.
Store in the refrigerator for up to 2 weeks or freeze for up to 3 months.