1 cup coarsely crushed Oreo cookies (about 10 cookies)
3/4 cup semisweet chocolate chips
6 tablespoons heavy whipping cream
Preheat oven to 325°. Place a greased 9-in. springform pan on a double thickness of heavy-duty foil (about 18 in. square). Wrap foil securely around pan. In a small bowl, mix cookie crumbs and sugar; stir in butter. Press onto bottom of prepared pan.
In a large bowl, beat cream cheese and sugar until smooth. Beat in cooled chips, creme de menthe, flour, creme de cacao and extract. Add eggs; beat on low speed just until blended. Pour half the batter over crust; sprinkle with crushed Oreos. Carefully spoon/pour remaining batter over top. Place springform pan in a larger baking pan; add 1 in. of hot water to larger pan.
Bake until center is just set and top appears dull, 75-80 minutes. Remove springform pan from water bath. Cool cheesecake on a wire rack 10 minutes. Loosen sides from pan with a knife; remove foil. Cool 1 hour longer. Refrigerate overnight, covering when completely cooled.
Remove rim from pan. Place chocolate chips in a small bowl. In a small saucepan, bring cream just to a boil. Pour over chocolate; stir with a whisk until smooth. Spread over cheesecake.