Heat the oven to 350°F (175°C). Grease the bottom and sides of a 9-inch springform pan, then line the bottom with parchment for easier release.

Combine the finely crushed chocolate sandwich cookies with the melted butter. Press the mixture firmly over the bottom of the pan and slightly up the sides, then bake for 8–10 minutes and cool for 10–15 minutes.

Reduce the oven temperature to 325°F (165°C). Beat the softened cream cheese and sugar on medium-low speed until smooth, taking care not to whip excess air into the mixture.

Mix in the peanut butter, sour cream, vanilla, and salt. Add the eggs one at a time, mixing only until each egg disappears into the batter.

Pour the filling over the cooled crust and smooth the top. Bake for 60–70 minutes, until the edges are set and the center has a slight wobble but does not look liquid.

Turn off the oven, leave the door slightly open, and let the cheesecake rest inside for 30–60 minutes. Cool it completely at room temperature, then refrigerate for at least 6 hours or overnight.

For the ganache, heat the heavy cream until steaming but not boiling. Pour it over the chocolate chips, let it stand for 2–3 minutes, and stir until glossy and smooth before spreading it over the chilled cheesecake.

Mix the topping peanut butter, softened butter, and powdered sugar until a firm dough forms. Roll the mixture into small balls and chill them briefly.

Melt the dipping chocolate with the shortening or coconut oil if using. Dip each peanut butter ball, leaving a small peanut butter circle visible at the top, then let the candies set on parchment.

Arrange the buckeyes over the ganache, adding chopped peanuts, chocolate curls, or mini peanut-butter cups if desired. Remove the cheesecake from the pan while thoroughly chilled and slice it with a warm, dry knife.