Preheat oven to 350 degrees F.
Spread 1/2 cup of the pecans on a baking sheet and toast them in the oven for 8 to 10 minutes, until lightly browned and fragrant. Let cool. (Do not turn the oven off.) Put the cooled nuts in a food processor or blender and process until smooth and buttery. Scrape the nut paste into a large bowl. Add the flour and work it in with a fork until completely incorporated. Set aside.
Heat the butter in a small saucepan over medium-high heat until it starts to foam and turns a light nutty brown. Pour into a small bowl.
Add the brown sugar, corn syrup, eggs, vanilla, and browned butter to the nut paste and stir until well blended. Fold in the remaining 5 cups pecans.
Pour the filling into the pre-baked pie shell. Bake for 30 to 40 minutes, until the filling is slightly puffed and the crust is golden brown. Transfer to a rack to cool. Serve warm or at room temperature.
Recipe reprinted with permission Larry Forgione from An American Place copyright 1996