Preparation:

Step 1: Prepare the Crust

1. Begin by crushing 24 Oreo cookies into fine crumbs. You can use a food processor or place the cookies in a zip-top bag and crush them with a rolling pin.
2. Transfer the crumbs to a bowl and mix them with 5 tablespoons of melted butter until the mixture resembles wet sand.
3. Press the crumb mixture firmly into the bottom and slightly up the sides of a 9-inch springform pan to form the crust. Use the back of a spoon or the bottom of a glass for even pressure.
4. Refrigerate the crust while you prepare the filling.

Step 2: Make the Peanut Butter Filling

1. In a large mixing bowl, beat the softened cream cheese until smooth and creamy. This step is essential to avoid lumps in the filling.
2. Add the peanut butter, powdered sugar, and vanilla extract to the bowl. Mix well until all ingredients are fully combined and smooth.
3. In a separate bowl, whip the heavy whipping cream until stiff peaks form. This will add lightness and a fluffy texture to the cheesecake.
4. Gently fold the whipped cream into the peanut butter mixture in batches, ensuring everything is evenly incorporated without deflating the whipped cream.

Step 3: Assemble the Cheesecake

1. Remove the prepared crust from the refrigerator.
2. Pour the peanut butter filling over the crust and spread it evenly using a spatula.
3. Smooth out the top for a neat finish. Cover the springform pan with plastic wrap or foil and refrigerate the cheesecake for at least 6 hours, preferably overnight, to allow it to set completely.

Step 4: Prepare the Chocolate Ganache Topping

1. Heat the heavy cream in a small saucepan over medium heat until it just begins to simmer. Be careful not to boil it.
2. Pour the hot cream over the chopped dark chocolate in a heatproof bowl. Let it sit for a minute to melt the chocolate.
3. Stir the mixture gently until smooth and glossy. Allow the ganache to cool slightly to a pourable consistency.

Step 5: Decorate and Serve

1. Remove the cheesecake from the refrigerator and carefully release it from the springform pan.
2. Pour the cooled ganache over the top, spreading it to the edges with a spatula or allowing it to drip slightly over the sides for a decorative effect.
3. Garnish with miniature peanut butter cups, chopped peanuts, or fresh raspberries for an extra layer of flavor and texture.