Pulse 20 mint Oreos into fine crumbs in a food processor.
Add the melted butter and pulse again to thoroughly combine.
Press the mixture evenly into the bottom and around the edges of a 9-inch springform pan.
Bake the crust for 10 minutes. Then, remove it from the oven.
Mint Cheesecake
Reduce the oven temperature to 325 degrees. Then, boil enough water to fill a roasting pan ¼ of the way up.
In a stand mixer, beat the cream cheese, sugar, and flour with the paddle attachment on medium-low for about 2 minutes. Then, add the eggs one at a time, beating after each addition. Finally, add the sour cream and vanilla and beat until combined.
Crush the Oreos and gently fold theminto the batter with a rubber spatula.
Wrap the springform pan in three layers of heavy-duty foil.
Place the wrapped pan in a larger roasting pan. Then, fill the roasting pan ¼ of the way up with the hot water. Bake for 60 to 70 minutes until the middle 2 inches of the cheesecake are jiggly.
Turn off the oven, crack the door, and leave the cheesecake inside it for an hour. Then, remove it from the oven and cool for another 30 minutes. Remove the springform pan from the water bath, and cool for another hour. Finally, chill the cheesecake uncovered for 3 hours.
Ganache
Break the chocolate bar into pieces and add them to a medium bowl.
Heat the heavy cream until it begins to bubble slightly.
Pour the heated heavy cream over the chocolate, add the mint extract, and let the mixture sit for 2 minutes.
Stir well until the ganache is smooth and glossy.
Pour the ganache over the chilled cheesecake.
Chill the cheesecake for another hour.
Mint Buttercream
Whip the softened butter for 1 minute on medium speed.
Add half the powdered sugar, salt, mint extract, and vanilla extract, and mix for 45 seconds or until blended.
Add the remaining powdered sugar and heavy cream and mix on medium for 1 to 2 minutes until rich and creamy.
Decorate
Pipe dollops of buttercream around the top edge of the cheesecake. Then, place mint cookies upright between the dollops.
Notes
Storage
Refrigerate for up to 4 days in a covered container.
You can freeze individual slices wrapped in plastic wrap and stored in an airtight, freezer-safe container for up to a month.
You can freeze an entire cheesecake by wrapping it in a double layer of plastic wrap and a layer of foil and freezing it for up to a month.
Never freeze your cheesecake for longer than a month, or it will become grainy.
Defrost the cheesecake overnight in the refrigerator before serving.
Tips
Be gentle when mixing your cheesecake batter at every stage. Keeping excess air out of the batter is key to ensuring the cheesecake doesn't collapse.
The key to a successful water bath is heating it before pouring it into the outer pan. You want the water to immediately fill the oven with steam and even heat.