Arrange pie crust in a 9-inch pie plate, and crimp or scallop the edges.
In a large bowl, whisk together butter, dark corn syrup, light corn syrup, sugar, eggs, Fireball, vanilla, and cinnamon.
Stir in pecan halves.
Pour into crust.
Bake at 350 degrees for about 45 minutes, or until edges are golden, and the center appears mostly set. It may be slightly jiggly right in the center, this is fine. Pie will set as it cools.
Remove from heat, and cool completely.
Chill, if desired, before serving - it seems to make it easier to cut!
Cut and serve. Top with whipped cream.