Pre-heat oven to 350 degrees. 

In a food processor or in a ziplock bag and rolling pin, crush Oreos into fine crumbs

In a large bowl, combine butter and oreo crumbs until evenly incorporated.

Place a spoonful in each cavity of a mini muffin pan or a parchment paper lined square baking pan.

Press oreo crust firmly into the bottom of the muffin tin.

Bake for 5 minutes then remove from the oven and set aside. Turn the oven down to 300 degrees. 

In a large mixing bowl, beat cream cheese until smooth with an electric mixer.

Add in sugar, cocoa, eggs and vanilla. Beat on low speed until until smooth and creamy. 

Using a cookie scoop, fill each cavity ¾ of the way with cheesecake batter.

Tap pan on the counter lightly to remove air bubbles.

Bake for a cooking time of 20 minutes.

The cheesecakes may jiggy slightly when done but remove from the oven before they begin to crack.

If you overcook the cheesecake and they begin to crack, they still taste amazing and you can cover the cracks with the ganache. 

Let cool on a wire rack to room temperature then move to the refrigerator to chill. 

In a small saucepan, simmer heavy cream over medium heat and remove just before it begins to boil.

Pour over semi-sweet chocolate and stir until smooth.

If using a square pan, cut mini cheesecakes into 1-inch squares.

Place a small spoonful of melted chocolate on the mini chocolate cheesecakes, it should just fill the middle before spilling over. 

For best results refrigerate overnight before serving chilled or at room temperature with your favorite toppings such as fresh berries, a chocolate drizzle, espresso beans, chocolate curls or mini chocolate chips. 

Store in an airtight container in the refrigerator for 3-5 days.