Preheat oven to 350°F. Blind bake the crust for about 20 minutes, until pale, but dry. I didn’t do this the first time I made the pie and wished I had; the bottom crust wasn’t as crisp as I’d like.
In a skillet melt the butter over medium heat, add the pecan pieces and cook until the nuts are toasty and the butter caramel color. Strain the nuts from the butter. Allow to cool for at least 15 minutes.
Whisk the eggs, brown sugar, corn syrup, vanilla, bourbon, and flour together.
Sprinkle the butter-toasted nuts and chocolate over the bottom of the pie crust. Pour the filling over the top and then arrange the pecan halves over the filling to create a spiral pattern.
Bake for about an hour, you may need to tent the crust if it starts to get dark before the pie is set. Let it cool completely before cutting.