Add 2.5 cups of crushed Oreo cookie crumbs and 0.25 cups of melted butter in a small mixing bowl. Stir to coat the crumbs completely.

Divide the crumb mixture evenly into cups. Use a spoon or the back of another cup to press down firmly.

Using a stand mixer or handheld mixer on medium speed, beat softened cream cheese for about 1 minute until smooth.

Add powdered sugar gradually, 0.5 cup at a time, mixing well after each addition.

Pour in cold heavy cream and vanilla; whip for 2-3 minutes until thickened and piping consistency is achieved.

Gently fold in remaining crushed Oreo crumbs into the filling.

Transfer filling into a piping bag with a decorative tip and pipe over the crumb base in each cup.

Top each cup with a mini Oreo cookie. Cover and refrigerate for at least 2 hours before serving.