Preheat the oven to 375ºF. Combine the graham cracker crumbs, Oreo cookie crumbs, butter, and 4 tablespoons of the granulated sugar in a medium bowl. Stir to thoroughly combine. Press the mixture firmly into a 9-inch pie pan and bake for 15 minutes. Remove the pan from the oven, let the crust cool completely, then wrap it with plastic wrap and place the pan in the freezer for at least 1 hour and for up to 2 weeks. Allow the crust to come to room temperature before filling.
Combine the cream cheese, confectioners' sugar, and milk in a large bowl. Beat with an electric mixer until well blended and smooth, about 1 minute on medium speed. Add the melted chocolate and the peanut butter and continue to blend for another minute on medium speed. Combine the cream with the remaining 2 tablespoons granulated sugar in another medium bowl. Beat with a whisk or electric mixer until stiff peaks form.
Gently fold the whipped cream into the chocolate and peanut butter mixture until thoroughly incorporated and smooth. Pour the filling into the pie crust. Smooth the top of the pie with a spatula, cover, and refrigerate for at least 4 hours before serving.
To serve, use a hot wet knife to slice the pie into 8 portions. Garnish with the peanuts and drizzle with the Rich Chocolate Sauce.
Rich Chocolate Sauce:.
In a small heavy saucepan, bring the half-and-half to a bare simmer over medium-low heat. Remove from the heat. Place the chocolate in a medium heatproof bowl. Whisk the half-and-half slowly into the chocolate. Add the vanilla and butter to the sauce and whisk until the butter is completely incorporated. The sauce can be kept refrigerated in an airtight container for several days, but it must be returned to room temperature before serving.