Step 1: Prepare the Crust

1. Preheat oven to 325°F (163°C).
2. Line a 12-cup muffin tin with cupcake liners.
3. In a small bowl, combine chocolate cookie crumbs and melted butter.
4. Press about 1 tablespoon of the mixture into each liner.
5. Bake for 5 minutes, then remove and let cool.

Step 2: Make the Cheesecake Filling

1. In a mixing bowl, beat cream cheese and peanut butter until smooth.
2. Add sugar and vanilla extract, mixing until combined.
3. Mix in the egg just until incorporated—do not overmix.

Step 3: Fill the Muffin Cups

1. Spoon the cheesecake mixture evenly over the cooled crusts, filling each about ¾ full.

Step 4: Bake the Mini Cheesecakes

1. Bake at 325°F for 15-18 minutes, or until the center is set but slightly jiggly.
2. Remove from the oven and let cool in the pan for 10 minutes before transferring to a cooling rack.

Step 5: Chill for Best Texture

1. Refrigerate for at least 2 hours (or overnight) to allow the cheesecakes to set fully.

Step 6: Add the Toppings

1. Top each cheesecake with a mini peanut butter cup or drizzle with melted chocolate.
2. Garnish with whipped cream, crushed peanuts, or cocoa powder if desired.

Step 7: Serve and Enjoy!

1. Remove the cupcake liners and serve chilled for the best texture.