Preheat your oven to 325°F (163°C) and prepare a standard muffin tin by lining it with cupcake liners. Place an Oreo cookie at the bottom of each liner.

In a large mixing bowl, beat the softened cream cheese and granulated sugar together until smooth, about 2-3 minutes. Add the vanilla extract, eggs, sour cream, and a pinch of salt, mixing until fully combined.

Spoon a generous heaping tablespoon of the cheesecake mixture onto each Oreo cookie, filling about halfway.

Warm the hot fudge sauce in the microwave for about 20 seconds until just melted. Drizzle a scant teaspoon of fudge on top of the cheesecake layer in each cup.

Using a toothpick or butter knife, lightly swirl the fudge into the top layer of the cheesecake batter.

Place the muffin tin in the preheated oven and bake for 40-45 minutes until set with a slightly jiggly center.

Remove the muffin tin from the oven and let the cupcakes cool completely in the tin before removing.