Preheat your oven to 350°F (175°C) and line a muffin tin with colorful cupcake liners.

Combine crushed chocolate cookies and melted butter, then spoon into muffin cups and press down.

Bake for 5 minutes until firm, then let cool completely.

Melt semi-sweet chocolate chips and butter in a saucepan, then combine with whisked cream and cornstarch until thickened.

Whisk together mascarpone cheese, powdered sugar, and vanilla until smooth.

Whip heavy cream until stiff peaks form, then fold into mascarpone mixture.

Layer cookie base with chocolate filling and mascarpone cream, chilling briefly between layers.

Dust assembled cups with cocoa powder and refrigerate for at least 4 hours before serving.