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

In a large bowl, combine oats, pecans, flaxseed, cinnamon, and salt.

In a separate bowl, whisk maple syrup, honey, oil, brown sugar, and vanilla until smooth.

Pour the wet mixture over the dry and toss until fully coated. Fold in the egg white if using.

Spread onto the prepared pan and press into a firm, even layer.

Bake 40–45 minutes, rotating once halfway, until deep golden. Do not stir for maximum clusters.

Cool completely on the pan (about 30 minutes) before breaking into clusters.

Store in an airtight container for up to 2 weeks.