In a small bowl, combine chopped pecans, graham cracker crumbs, and 1/3 cup butter. Press crumb-nut mixture into the bottom and up sides of 8-inch pie pan. In a large mixing bowl combine sugar, flour, baking powder, salt, chocolate, eggs, vanilla, and 1/2 cup butter. Beat with electric mixer on medium until well blended. Pour batter into prepared crust. Cover with foil; bake in a preheated 350° oven for 20 minutes.
Remove foil and bake 10 minutes longer, or until a wooden pick or cake tester inserted in center comes out clean.
Serve brownie pie with whipped cream or whipped topping or ice cream.
Optional whipped cream for garnish:
Whip cream until almost stiff. Add sugar and vanilla; beat until cream holds peaks. Spread over top of cooled pie or use as a dessert or shortcake topping.
Calories per serving (based on 8 servings): 521