Step 1: Make the Crust Preheat oven to 325°F (163°C). Crush the Oreos into crumbs and mix with melted butter. Press into a 9-inch springform pan and bake for 10 minutes. Let cool. Step 2: Make the Cheesecake Filling Beat cream cheese and sugar until smooth. Add eggs one at a time. Mix in sour cream, vanilla, buttermilk, cocoa, red food coloring, and salt. Pour over crust. Step 3: Bake the Cheesecake Wrap the pan with foil or use a water bath. Bake for 55–65 minutes. Turn off oven and leave inside with door ajar for 1 hour. Chill in fridge for 4 hours or overnight. Step 4: Make Raspberry Sauce Simmer raspberries, sugar, and lemon juice in a saucepan. Add cornstarch slurry and cook until thick. Strain to remove seeds and cool. Step 5: Decorate Use a toothpick to poke holes and drizzle raspberry sauce to mimic vampire bites. Chill until ready to serve.