Preheat oven to 180°C (350°F).
In a large bowl, mix together the oats, hazelnuts, coconut flakes, and cocoa powder.
In a separate bowl, whisk together the maple syrup, coconut oil, and vanilla extract.
Pour the wet ingredients over the dry ingredients and mix until well combined.
Spread the granola mixture onto a baking sheet lined with parchment paper.
Bake for 20-25 minutes, stirring halfway, until the granola is golden brown.
Allow to cool completely before storing in an airtight container.
