Preheat your oven to 350 degrees F.
Line 9 muffin cups with paper liners and give them a quick spray with nonstick cooking spray.
In a large bowl, mix together pecans, brown sugar, and flour.
It helps to use a spatula to combine everything evenly.
In a separate bowl, beat the eggs until they’re light and foamy.
Add in the melted butter and stir until well combined.
Pour the egg mixture into the bowl with the dry ingredients.
Mix just until everything is moist, being careful not to overmix.
Divide the muffin batter evenly among the prepared muffin cups.
Bake for 20-25 minutes or until the tops are golden brown.