Start by spraying a 9-inch pie pan with nonstick spray for easy removal. In a food processor, blend Oreo cookies until they form fine crumbs. Combine the crumbs with melted unsalted butter, mixing until well-coated. Press the mixture firmly into the bottom and up the sides of the pie pan. Place it in the freezer for about 15 minutes to set while you prepare the filling.

In a large mixing bowl, beat room temperature cream cheese, white granulated sugar, and unsweetened cocoa powder together until smooth and creamy. Then, add pure vanilla extract, sour cream or Greek yogurt, and melted chocolate, mixing until fully combined and smooth.

In another bowl, beat cream cheese and granulated sugar until creamy and well-blended. Add creamy peanut butter, vanilla extract, and sour cream, mixing thoroughly until it reaches a smooth consistency.

Chill a mixing bowl for a few minutes, then pour in heavy cream and powdered sugar. Whip on medium-high speed until stiff peaks form, typically taking 3–5 minutes. Carefully fold half of this whipped cream into both the chocolate and peanut butter mixtures separately.

Spread the chocolate layer evenly onto the chilled Oreo crust, smoothing it out with a spatula. Carefully spoon the peanut butter layer on top, spreading it evenly over the chocolate layer. Drizzle melted peanut butter over the top and use a toothpick to create a beautiful swirl.

Cover the assembled Chocolate Peanut Butter Pie with foil or plastic wrap and refrigerate for at least 6 hours or overnight for the best results.