Preheat the oven to 325 degrees. Line a 12 x 17 baking sheet with parchment paper.
Spread the chopped walnuts and pecans in a single layer on the prepared baking sheet.
Scatter the pumpkin seeds on top.
In a small bowl, stir together the maple syrup, coconut oil, vanilla, and cinnamon. Pour over the nut mixture and then use a spatula to stir it all together. You want everything evenly coated. Spread in an even layer.
Bake for 30 minutes.
Remove from oven and let cool completely. The granola will get crispy as it cools.
Once completely cooled, store in an airtight container at room temperature. It will be good for at least 2 weeks, but I bet you'll have it all gobbled up long before then!