Preheat oven to 300°F. Line a baking sheet with parchment paper and set aside.
Mix together the oats, pecans, brown sugar, cinnamon and fine sea salt in a large mixing bowl. Set aside.
In a small saucepan, melt the butter over medium heat. Continue cooking 3-5 minutes while swirling occasionally. You'll know it's done when the butter is amber in color and has a nutty aroma. Remove from heat and stir in the maple syrup and vanilla.
Pour the brown butter maple mixture over the dry oat mixture and stir until fully coated.
Spread the combined mixture onto the prepared baking sheet and bake for 35 minutes, stirring every 10 minutes so that it toasts evenly.
Allow the granola to fully cool before breaking into clusters. Store in an airtight container.
