1. For filling, in a mixing bowl beat eggs lightly with a rotary beater or a fork until combined. Stir in corn syrup, sugar, peanut butter, and vanilla. Mix well.
2. Sprinkle the 1/2 cup chocolate pieces over the bottom of an unbaked pastry-lined 9-inch pie plate. Pour filling into pie shell. Cover edge of pie with foil.
3. Bake in a 375 degree F oven for 20 minutes. Remove foil. Bake for 15 to 20 minutes more or until knife inserted near the center comes out clean. Cover and chill within 2 hours. Garnish with whipped topping, remaining chocolate pieces, and peanuts, if desired. Makes 10 servings.