Preheat your oven to 350°F. In a mixing bowl, combine chocolate cookie crumbs and melted butter. Mix until well combined and resembles wet sand.
Press the mixture into the bottom and up the sides of a mini muffin tin to form crusts. Bake for 5-7 minutes until set. Remove from oven and let cool completely.
In another bowl, beat together peanut butter and powdered sugar until smooth and creamy.
In a separate bowl, whip the heavy cream and vanilla extract until stiff peaks form. Gently fold the whipped cream into the peanut butter mixture until fully combined.
Spoon or pipe the peanut butter filling into the cooled cookie crusts, filling them to the top.
In a small saucepan, heat the chopped chocolate and milk over low heat, stirring until melted and smooth.
Drizzle the melted chocolate over the filled mini pies.
Refrigerate the pies for at least 1 hour to set before serving.