Make crust
Preheat oven to 350F and butter and flour pie pan. Thaw crust and roll out into a circle slightly larger than the top of your pie pan.
Lay crust into pie pan, and fold edges under themselves. Crimp edges and pierce bottom and sides of crust with a fork.
Chop 1 cup pecans, and mix with 1 cup maple syrup, 3 beaten eggs, vanilla. Pour filling into pie crust.
Add remaining pecans on the top of the filling, in a circular fashion.
Cover crust edges with foil, and bake for 30 minutes. Remove foil and bake for another 10-20 minutes until the center is not jiggly and edges are golden brown.