Melt chocolate wafers in a small microwave safe bowl, stirring every 30 seconds.

Generously spread melted chocolate around the rim of the cup. Press Thin Mint cookies on the melted chocolate and drizzle chocolate inside the cup; place cup in the freezer.

Blend vanilla ice cream, milk and 4 cookies together. Add more milk depending on your milkshake consistency preference.

Pour into glass, top with whipped cream and crushed cookie pieces.