Preheat the oven to 350°F (175°C). Crush Oreo cookies and mix with melted butter. Press into a 9-inch springform pan. Bake for 10 minutes, then reduce temperature to 325°F (163°C).

In a bowl, beat cream cheese and sugar until smooth. Add cocoa powder, sour cream, vinegar, vanilla, and salt, mixing until combined. Then add food coloring and eggs, mixing gently.

Wrap the bottom of the springform pan in aluminum foil. Pour cheesecake filling over cooled crust.

Place the pan in a larger roasting pan, fill with hot water halfway up the sides. Bake at 325°F (163°C) for 60-70 minutes until edges are set.

Turn off the oven, leave cheesecake to cool with door ajar for 30 minutes, then cool completely and refrigerate for at least 4 hours.

Beat additional cream cheese and butter until fluffy. Add confectioners' sugar and a splash of vanilla, mixing until smooth.

Unmold the cheesecake and frost the top. Optionally pipe decorative frosting and add berries or chocolate shavings.