Set the cream cheese on the counter about 1 hour before you start so it becomes completely soft. Move the frozen whipped topping to the refrigerator the night before, or thaw it on the counter for about 30 minutes. Preheat your oven to 350°F (175°C). Chop the mini peanut butter cups and the roasted peanuts, then set them aside for the topping. Measure out the milk and keep it in the refrigerator until you need it.
If you are starting with whole graham crackers, pulse about 10 full sheets in a food processor until they look like fine sand. Add the 1 1/2 cups of graham cracker crumbs to a medium bowl along with the 1/4 cup of granulated sugar, and stir them together. Pour in the 6 tablespoons of melted butter and mix with a fork until the crumbs look like wet sand and clump when squeezed. Tip the mixture into a 9-inch pie dish. Press it firmly across the bottom and up the sides, using the flat bottom of a measuring cup to pack it down tightly.
Bake the crust for 8 to 10 minutes, until it smells toasty and the edges look slightly darker. Remove it from the oven and set the dish on a wire rack. Let the crust cool completely, which takes about 30 minutes. While you wait, check that your cream cheese is soft and your whipped topping is fully thawed.
Add the 8 ounces of softened cream cheese to a large bowl. Beat with an electric hand mixer on medium speed for about 1 minute, until smooth and creamy. Add the 1/2 cup of creamy peanut butter, the 1 cup of powdered sugar, and the 1 teaspoon of vanilla extract. Beat again for about 2 minutes, scraping the sides of the bowl once or twice, until the mixture is fluffy with no lumps. Measure out 1 1/2 cups from the thawed tub of whipped topping and gently fold it in with a rubber spatula. Stop folding as soon as no white streaks remain.
Spoon the peanut butter mixture into the cooled crust. Use an offset spatula to spread it into an even layer, all the way to the edges. Smooth the top so the pudding layer will sit flat. Place the pie in the refrigerator for 10 to 15 minutes while you make the pudding.
Pour the 3 cups of cold whole milk into a large bowl. Add both boxes of instant chocolate pudding mix. Whisk steadily for about 2 minutes, until the mixture thickens and there are no dry pockets of powder. Let the pudding rest for 5 minutes so it can finish thickening to a spreadable consistency.
Take the pie out of the refrigerator. Spoon the thickened pudding gently over the peanut butter layer, starting near the center. Use the offset spatula to spread the pudding to the edges in one smooth sweep. Avoid pressing hard, so the two layers stay separate and clean.
Return the pie to the refrigerator, uncovered, for 30 minutes so the surface of the pudding firms up. Cover the pie loosely with plastic wrap once the top is no longer sticky. Chill for at least 4 hours, or overnight, until the layers are fully set and slice cleanly.
Spread the remaining whipped topping over the chocolate layer, or pipe it in swirls using a piping bag with a star tip. Scatter the 1/2 cup of chopped mini peanut butter cups over the top. Sprinkle on the 2 tablespoons of chopped roasted peanuts. Drizzle the 2 tablespoons of chocolate syrup in thin zigzag lines across the pie. Slice with a sharp knife dipped in hot water and wiped dry between cuts, then serve chilled.