Pre-heat oven to 325 F.

Prepare the spring form pan with aluminum foil around the bottom and outsides so no water gets in while the cheesecake is baking.

Place Oreo's in a zip lock bag and smash until crumbs are smooth.

Add melted butter and Oreo's to a bowl and mix well.

Press the Oreo crust into the bottom of the spring form pan.

Cut a piece of parchment paper to the length needed to go around the inside of the spring form pan, fol in half and place around the inside of the pan, against the pan's edge.

In a mixing bowl, add room temperature cream cheese, sugar, vanilla, cocoa powder, sour cream, flour and eggs and blend until smooth.

Pour mixture into the pan with the Oreo crust on the bottom and if using parchment paper it will be against the sides of the pan.

Place cheesecake into a larger pan and fill the larger pan with enough warm water to come up to about 3/4's of the way on the sides of the spring form pan.

Bake for ~1 hour and 45 minutes. Cake will be a little giggly but the center will seem set, there should be a fairly firm skin formed on the top of the cake. The cake will rise quite a bit but that rise will slowly sink down as the cake cools.

Remove from oven and water bath and let cool completely before removing from the spring form pan.

When cooled, top with chocolate ganache, frost the top with butter cream and top with crushed and whole Oreo's.

Directions for chocolate ganache:

Heat milk on stove top or microwave until steaming.

Pour over chocolate chips in a bowl and cover, let set for a few minutes then stir until chocolate ganache is smooth. If chocolate needs to melt more you can microwave in 5 second increments until ganache is smooth.

ganache will thicken as it cools. If using as a drip, you may have to add more milk to thin out or if ganache seems thin then add more chocolate to get right consistency.

Directions for buttercream frosting:

Add all ingredients into a mixing bowl and whisk until smooth, add more milk to thin if desired.

Pipe buttercream on top.