Preheat Oven:
Preheat oven to 325°F (160°C). Grease a 9-inch springform pan and wrap the bottom with foil to prevent leaks if using a water bath.

Make Crust:
Crush Oreo cookies into fine crumbs (using a food processor or zip-top bag and rolling pin). Mix with melted butter. Press firmly into the bottom of the pan. Bake for 10 minutes, then let cool.

Make Cheesecake Filling:
In a large bowl, beat cream cheese until smooth. Add sugar and beat until combined. Mix in sour cream, then eggs one at a time. Stir in vanilla, mint extract, and heavy cream.
Add green food coloring if using, and gently swirl in melted chocolate for a marbled effect or mix completely for a full chocolate mint flavor.

Bake:
Pour filling over cooled crust. Bake for 55–65 minutes, or until center is set but still slightly jiggly. Turn off oven, crack the door, and let cheesecake cool inside for 1 hour.

Chill:
Remove cheesecake from oven, cool to room temperature, then refrigerate for at least 4 hours or overnight.

Serve:
Top with whipped cream, chocolate shavings, crushed Oreos, or mint leaves before serving. Slice and enjoy chilled!