Heat the oven to 350 degrees F.
To make crust, combine graham cracker crumbs, sugar and butter. Press down into the bottom of a pie pan to form a crust and bake for about 8 minutes.
In the top of a double boiler, melt together candy bars, peanut butter, and half-and-half, stirring until smooth. Remove from heat and allow to cool slightly. Fold in whipped topping, pour into crust, and freeze for 4 to 6 hours before serving. (For a richer pie, substitute 2 cups heavy cream, whipped with 1/2 cup sugar until stiff peaks form, in place of prepared whipped topping.)
When ready to serve, top with additional whipped topping and drizzle wth chocolate syrup. Store in refrigerator.