Preheat the oven to 300°F and line a half sheet pan with parchment paper.
In a large bowl, combine the oats, pecans, almonds, kosher salt and cinnamon.
Place the brown sugar, oil, maple syrup, vanilla and maple syrup in a spouted measuring cup and stir until combined.
Pour the wet ingredients over the oat mixture and mix well, until all the oats and nuts are lightly coated. Spread the granola in an even layer on the prepared baking pan.
Bake until lightly golden, about 30 minutes. Stirring and rotating the pan 180° at the half way point.
Allow the granola to cool undisturbed on the pan for at least 45 minutes. If desired, add chocolate chips or flaked coconut.
Notes
Store maple granola in an airtight container at room temperature for up to 2 weeks. The granola can also be frozen in a zip top bag or airtight container for up to 3 months.