Heat oven to 350 degrees F. Spray an 8-inch round springform pan with cooking spray, then line with foil.

Combine ingredients for the crust in a food processor; pulse until fine crumbs form. Press crust evenly into the bottom of the prepared pan. Bake 15 minutes to set.

Meanwhile, make the cheesecake: Place chocolate chips in a microwave safe bowl. Heat chocolate chips in microwave for 30 seconds; stir. Repeat until chips are completely melted.

Blend cream cheese, 2/3 cup sugar and 1/2 cup sour cream in food processor until smooth. Scrape down the sides, then add eggs and melted chocolate. Pulse just until combined.

Carefully pour the filling on top of the pre-baked crust and spread into an even layer. Bake 20 minutes until filling is just set in the center and the edges puff slightly.

Meanwhile, mix remaining sugar and sour cream with the creme de menthe in a medium bowl until smooth. Carefully pour or spoon filling on top of set cheesecake in an even layer. Bake 15 to 20 minutes more until filling is just set but still a little loose (it will completely set as it cools and is refrigerated).

Transfer to a cooling rack to cool completely. Once fully cooled, cover and chill at least 4 hours or overnight.

When cheesecake is fully set, carefully remove the edges of the pan and the foil. Garnish top with whipped cream and chocolate shavings, if desired.