Heat the oven to 325˚ F. Line a 13 x 18-inch baking sheet with a silicone baking mat or parchment paper.
In a large bowl, combine the cinnamon, oats, almonds, coconut, flax or chia seeds, and almond or hazelnut flour. Stir to blend, and set aside.
In a small saucepan, combine the maple syrup, brown sugar, water, vanilla, and salt. Bring to a boil over medium heat, stirring to dissolve the sugar and salt. Remove from the heat and let cool to warm room temperature.
Once the syrup mixture is cooled, add the olive oil and egg white. Whisk to incorporate. Pour into the bowl with the oat mixture and mix well with a spatula.
Spread the mixture evenly across the prepared baking sheet. Press the mixture down firmly, compacting it. Bake for 45 minutes or until golden brown, rotating the sheet about halfway through the baking time to ensure even browning.
Leaving the oven on, transfer the baking sheet to a wire rack and let cool until the surface of the granola is crisp. If the surface is still tacky, return the pan to the oven and bake 10-15 minutes more, checking every 5 minutes to avoid over browning.
Once cook, break the bark into pieces and store in an airtight container.