Adjust the oven rack to the lower-middle position. Preheat oven to 350°F (180°C) or 160° fan oven, line a muffin pan with paper liners, and set aside.
Add 12 Oreos to a high speed food processor; blend until only fine crumbs remain. Add the melted butter and pulse until the mixture resembles wet sand.
Divide the Oreo crumb mixture evenly between the 12 prepared muffin cavities, press down firmly with your fingers or the back of a spoon; set aside.
In the bowl of a stand mixer, (or using a hand mixer and mixing bowl) beat the softened cream cheese and granulated sugar until smooth and creamy. Add the eggs, one at a time, blending well after each addition. Scrape the sides of the bowl as necessary to ensure even mixing. Beat in the sour cream, vanilla, and salt.
Finally, add the chopped Oreos and mix well.
Divide the cheesecake batter between the 12 muffin cups, being careful to not overflow the paper liners.
Bake the cheesecakes in the oven for 12-15 minutes, or until the center is set and no longer jiggly. Remove from the oven and allow to cool for 30 minutes before placing into the fridge for 90 minutes to chill completely.
Place the heavy cream and powdered sugar in the bowl of a stand mixer fitted with the whisk attachment and whip until firm peaks form. Use a piping bag to add a dollop of whipped cream to each of the chilled cheesecakes, then top with a mini Oreo.