**Crust:**

1. Use a food processor to turn the Oreos into fine crumbs. Alternatively, seal the cookies in a ziplock bag and crush them with a rolling pin or any heavy object.
2. Mix the melted butter with the crumbs until well combined. Press this mixture into a 9-inch springform pan and refrigerate until needed. A flat-bottomed glass or measuring cup can help evenly press it down.

**Ganache:**

1. Roughly chop the chocolate and place it in a heat-proof bowl.
2. Heat the cream in the microwave for 45 seconds to 1 minute.
3. Pour the hot cream over the chocolate and let it sit for 5 minutes.
4. Whisk the mixture until smooth, then set it aside.

**Filling:**

1. In a stand mixer, beat the cream cheese on medium-high until smooth (2-3 minutes).
2. Add granulated sugar, sour cream, and vanilla; mix until smooth.
3. With the mixer on low, add the eggs and mix until fully incorporated.

**Assembly:**

1. Preheat the oven to 350°F.
2. Spoon ⅓ of the cheesecake mixture onto the crust.
3. Add ⅓ of the ganache in dollops and repeat twice.
4. Use a spoon or knife to swirl through the chocolate ganache.
5. Bake for 50-60 minutes until the edges are set and the center is slightly jiggly.
6. After baking, turn off the oven, crack it open, and let the cheesecake cool inside for 30 minutes.
7. Remove the cheesecake, run a knife along the edges, and let it cool completely before refrigerating for at least 1 hour.