From Cooks Illustrated, here are their notes:
For a pleasantly sweet, chocolaty crust, we use Oreo cookies processed with butter and a bit of sugar, and bake the crust until crisp. For the filling, we melt milk chocolate with a small amount of cream for just the right amount of chocolate flavor. Unlike traditional cheesecake that is baked in a water bath for gentle, moderate cooking, we simplified our cheesecake by baking it at a low temperature (250 degrees). To temper the heat even more, we covered the cheesecake with foil for the first hour and then uncovered it to finish cooking. Decorated with a chocolate drizzle, this is an impressive dessert that comes together easily.
Our favorite milk chocolate is Dove Silky Smooth Milk Chocolate. For the crust, use the entire Oreo cookie, filling and all. The cheesecake needs to be refrigerated for at least 8 hours before serving.
Ingredients
16 Oreo sandwich cookies, broken into rough pieces
1 tablespoon sugar plus 1/2 cup (3 1/2 ounces)
2 tablespoons unsalted butter, melted
8 ounces milk chocolate, chopped
1/3 cup heavy cream
2 tablespoons unsweetened cocoa powder
1/4 teaspoon salt
1 1/2 pounds cream cheese, softened
4 large eggs, room temperature
2 teaspoons vanilla extract
Instructions
1. Adjust oven rack to middle position and heat oven to 350 degrees. Grease bottom and sides of 9-inch nonstick springform pan.2. Process cookies and 1 tablespoon sugar in food processor until finely ground, about 30 seconds. Add melted butter and pulse until combined, about 6 pulses. Transfer crumb mixture to prepared pan and press firmly with bottom of dry measuring cup into even layer in bottom of pan. Bake until fragrant and set, about 10 minutes. Let cool completely on wire rack.
3. Reduce oven temperature to 250 degrees. Combine 6 ounces chocolate and cream in medium bowl and microwave at 50 percent power, stirring occasionally, until melted and smooth, 60 to 90 seconds. Let cool for 10 minutes. In small bowl, whisk cocoa, salt, and remaining 1/2 cup sugar until no lumps remain.
4. Using stand mixer fitted with paddle, beat cream cheese and cocoa mixture on medium speed until creamy and smooth, about 3 minutes, scraping down bowl as needed. Reduce speed to medium-low, add chocolate mixture, and beat until combined. Gradually add eggs, one at a time, until incorporated, scraping down bowl as needed. Add vanilla and give batter final stir by hand until no streaks of chocolate remain.
5. Pour cheesecake mixture into cooled crust and smooth top with spatula. Tap cheesecake gently on counter to release air bubbles. Cover pan tightly with aluminum foil (taking care not to touch surface of cheesecake with foil) and place on rimmed baking sheet. Bake for 1 hour, then remove foil. Continue to bake until edges are set and center registers 150 degrees and jiggles slightly when shaken, 30 to 45 minutes. Let cool completely on wire rack, then cover with plastic wrap and refrigerate in pan until cold, about 8 hours. (Cake can be refrigerated for up to 4 days.)
6. To unmold cheesecake, remove sides of pan, slide thin metal spatula between crust and pan bottom to loosen, and slide cake onto serving platter. Microwave remaining 2 ounces chocolate in small bowl at 50 percent power, stirring occasionally, until melted, 60 to 90 seconds. Let cool for 5 minutes. Transfer to small zipper-lock bag, cut small hole in corner, and pipe chocolate in thin zigzag pattern across top of cheesecake. Let cheesecake stand at room temperature for 30 minutes. Using warm, dry knife, cut into wedges and serve.