Preheat the oven to 350°F (175°C).
Lightly grease a mini cheesecake pan and set it aside.
Blend 10 Oreo cookies into fine crumbs.
Add melted butter to the crumbs and mix thoroughly.
Divide the crumb mixture evenly into the cheesecake cavities.
Press the crumbs firmly to form a flat crust.
Bake the crusts for 5 minutes.
Reduce the oven temperature to 325°F (163°C).
In a large bowl, beat cream cheese and sugar until smooth.
Add vanilla, cookie pieces, and the egg; mix until just combined.
Fill each cavity about 3/4 full with the cheesecake filling.
Tap the pan gently on the counter to remove air bubbles.
Bake for 15–18 minutes, until set.
Cool cheesecakes completely on a wire rack.
Refrigerate for 4–6 hours or overnight.
Whip heavy cream, powdered sugar, and vanilla until stiff peaks form.
Carefully remove cheesecakes from the pan.
Top each cheesecake with whipped cream.
Garnish with a mini Oreo cookie.
Keep refrigerated until ready to serve.