Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a large mixing bowl, combine the rolled oats, chopped nuts, and cocoa powder.
In a separate bowl, mix together the honey or maple syrup, melted coconut oil, and vanilla extract.
Pour the wet ingredients over the dry ingredients and mix until well combined.
Spread the mixture evenly on the prepared baking sheet.
Bake for 25-30 minutes, stirring halfway through, until the granola is golden brown and crunchy.
Remove from the oven and let it cool completely. Once cooled, stir in the dark, white, and milk chocolate chips.
Store in an airtight container for up to two weeks.