This is very rich, if you like chocolate. I found this recipe as a chocolate truffle cheesecake in Taste of Home, however I've changed it into an Oreo cheesecake. I hope you enjoy. You will use a whole package of Oreos, so no snacking : )
In a small bowl, combine Oreo crumbs and butter. Press onto the bottom of a greased (only bottom) 9-inch springform pan. Take your 16 cookies and line the sides (cookies should be standing up; you may need to trim the 16th cookie)(also may need more or less if have bigger or smaller pan).
Heat oven to 325°F.
For filling, melt chocolate chips in a small heavy saucepan or microwave; stir until smooth. Remove from the heat; add cream and mix well. Set aside.
In a large mixing bowl, beat cream cheese and sugar until smooth. Add cocoa and beat well. Add eggs; beat on low just until combined. Stir in vanilla and reserved chocolate mixture just until blended. Breakup the remaining cookies from the package, should be larger pieces (I break the cookie twice). Pour over crust.
Bake for 45-50 minutes or until center is almost set (mine is done at 35 min, just make sure to keep an eye on it).
For topping, melt chocolate chips in a heavy saucepan or microwave, stir until smooth. Stir in cream and vanilla, Kahlua and Irish cream; mix well. Spread over filling. Cool pan on a wire rack for 10 minutes. cool 1 hour longer. Refrigerate overnight.
Remove sides of pan. Just before serving, garnish with whipped creme, optional. Refrigerate leftovers. Yield: 12 servings.