Combine the crushed cookie crumbs with melted butter in a bowl, stirring until the mixture looks evenly coated and holds together when pressed.
Press this mixture firmly into the bottom of a springform pan, creating an even crust. Chill in the fridge for 30 minutes to set.
Gently melt the dark chocolate using a double boiler or microwave, stirring until the chocolate is glossy and smooth. Let it cool slightly.
In a separate bowl, whisk together the peanut butter, sifted powdered sugar, and vanilla until creamy and well combined.
Pour the melted chocolate into the peanut butter mixture, folding gently until the filling is smooth and uniform in color.
Pour the rich filling over the chilled crust, spreading it evenly with a spatula for a smooth top.
Refrigerate the tart for at least 4 hours, or overnight, until the filling is firm and glossy.
Once set, decorate the top with chopped peanuts, chocolate shavings, or a drizzle of melted chocolate for added texture and visual appeal.
Let the tart sit at room temperature for 10-15 minutes before slicing to ensure clean cuts and enhanced flavor.