Preheat the oven to 350°F (175C/155C Fan) and line a 24-hole mini muffin pan with mini cupcake liners.
Begin by mixing together the Oreo crust ingredients - the crushed Oreo cookies and melted butter.
Once you have a moistened crumb mixture, spoon this into the prepared liners - about ½ teaspoon per liner. Divide evenly amongst the cases and press firmly into the bases. Set aside while making the filling.
In a mixing bowl, beat together the cream cheese and sugar until smooth.
Add the egg, vanilla and sour cream, whisking to combine. Finally add in the crushed Oreo cookies and stir to evenly distribute.
Spoon the filling on top of the Oreo bases - about 1 teaspoon per case. Divide evenly.
Place the pan in the centre of the preheated oven and bake for about 12 minutes until set. (see note)
Once baked, remove from the oven and allow to cool - first on the counter and then in the refrigerator for at least 4 hours to thoroughly chill.
When ready to serve, whip the heavy cream, powdered sugar and vanilla extract until stiff peaks form. (see note)
Transfer the cream to a piping bag fitted with a star nozzle and pipe dollops on the top of each chilled mini cheesecake. (see note)
Top each cheesecake bite with a mini Oreo cookie for a finishing touch before serving.