Preheat the oven to 300°F (150°C) and line a baking sheet with parchment paper.

In a large bowl, combine oats, nuts, protein powder, ground flaxseed, and salt.

Pour in the maple syrup and oil, stirring until everything is evenly coated.

Mix in the egg white if using; this helps form crunchy clusters.

Spread the mixture evenly on the prepared baking sheet.

Bake for 45–60 minutes, rotating the pan halfway through, until lightly golden.

Remove from the oven and let the granola cool completely on the pan.

Once cooled, break into clusters and stir in any optional add-ins.