Preheat oven & prep pan: Preheat your oven to 325°F. Double wrap the bottom and sides of a 9-inch springform pan with foil to prevent leaks. Lightly spray the inside of the pan with non-stick spray.
Make Mint Oreo crust: Pulse 20 Mint Oreo sandwich cookies in a food processor until finely pulverized. No processor? Place cookies in a large zip-top bag, remove extra air, seal, and crush with a rolling pin or heavy pan.
Combine crust ingredients: In a mixing bowl, combine the cookie crumbs with 1/4 cup melted butter. Stir until the mixture is fully coated and press evenly into the bottom and slightly up the sides of the prepared springform pan using your fingers or the back of a spoon. Set aside while you prepare the filling.
Beat cream cheese: In a large mixing bowl, beat 24 ounces of room-temperature cream cheese until creamy and smooth. This ensures a lump-free cheesecake filling.
Add sugar and eggs: Mix in 3/4 cup sugar until combined. Beat in 3 large eggs, one at a time, making sure each is fully incorporated before adding the next.
Add remaining filling ingredients: Fold in 3/4 cup sour cream, 1/2 teaspoon salt, and 1 teaspoon mint extract until smooth.
Prepare green swirl portion: Scoop out about 1/3 cup of the cheesecake filling into a separate small bowl. Add a few drops of Neon Green gel food coloring and mix until evenly combined.
Assemble cheesecake: Pour the remaining white cheesecake filling over the Oreo crust and smooth with a spatula. Drop spoonfuls of the green filling across the top in alternating lines. Use a knife or chopstick to gently swirl the green into the white filling, creating a marbled pattern. Don’t over-swirl; a little swirl goes a long way.
Prepare water bath: Boil about 2 cups of water on the stove or in a microwave-safe container. Place the springform pan in a larger roasting pan. Carefully pour boiling water into the roasting pan so it comes about halfway up the sides of the springform pan.
Bake cheesecake: Bake at 325°F for 75 minutes, or until the center is just set (it will still slightly jiggle). Turn off the oven, open the door, and let the cheesecake sit in the oven for 1 hour.
Cool and chill: Remove the springform pan from the water bath and carefully unwrap the foil. Run a thin-bladed knife around the edges to loosen the cheesecake. Let it cool completely on a cooling rack, then refrigerate overnight to fully set and develop flavor.
Make Andes mint topping: In a small saucepan, combine 4 oz chopped Andes mint chocolates with 1/3 cup cream over low heat. Stir until smooth. Let cool for 5 minutes, then pour evenly over the chilled cheesecake. Garnish with additional chopped Andes mints as desired. Chill in the refrigerator until ready to serve.