Preheat the oven to 350 degrees.
Place pecans on a baking sheet and bake until roasted, about 5-7 minutes. Check frequently as pecans can burn very quickly.
In a saucepan, melt butter over medium heat. Add the dark corn syrup, light corn syrup, brown sugar, flour, vanilla, and salt and mix until incorporated and fully melted.
Remove from heat, allow to cool for about 5 minutes, and whisk in eggs and stir in chopped pecans. Pour pecan mixture into an unbaked pie shell. Arrange whole pecans over the top of the pie.
Brush butter on the edges of the pie crust and transfer in a preheated oven. Bake for about 40-50 minutes, or until the filling barely moves when shaken. If the pie is browning too quickly, place foil over the top of the pie until done.
Allow pie to cool to room temperature. Slice and serve with a scoop of vanilla ice cream if desired.