Step 1: Prepare the Pan

Line an 8×8 inch square pan with parchment paper, leaving an overhang on two sides. This makes it easy to lift the finished bars out of the pan cleanly for slicing. Set aside.

Step 2: Make the Oreo Crust

Carefully twist apart the 18 Oreo cookies and scrape out the cream filling — the filling adds excess fat to the crust and prevents it from setting as firmly. Place the chocolate wafers in a food processor and pulse until you have fine, even crumbs. Alternatively, place the cookies in a zip-top bag and crush them with a rolling pin. Transfer the crumbs to a bowl, pour in the melted butter, and stir until every crumb is evenly coated and the mixture clumps together when pressed. Press the mixture firmly and evenly into the bottom of the prepared pan, using the flat bottom of a glass or measuring cup for a compact, level layer. Refrigerate while you prepare the filling.

Step 3: Make the Cheesecake Filling

In a large bowl, beat the softened cream cheese with an electric mixer on medium speed until completely smooth and fluffy, with no lumps remaining. Add the granulated sugar and continue beating until fully incorporated and the mixture is creamy and uniform. In a separate clean, cold bowl, beat the heavy whipping cream with an electric mixer until stiff peaks form — the cream should hold its shape firmly when the beaters are lifted. Gently fold the whipped cream into the cream cheese mixture in two or three additions, using a spatula and slow, deliberate strokes to keep the mixture as light and airy as possible. Fold in the chopped Oreo cookies until evenly distributed throughout the filling.

Step 4: Fill and Chill

Remove the chilled crust from the refrigerator. Spoon the cheesecake filling over the crust and spread it into an even, smooth layer using a spatula. Tap the pan gently on the counter a couple of times to eliminate any air pockets. Cover with plastic wrap and refrigerate for 4 to 6 hours, or overnight, until the filling is fully set and firm to the touch.

Step 5: Make the Chocolate Topping

Place the finely chopped milk chocolate in a heatproof bowl. Heat the 50 g of heavy cream in a small saucepan over medium heat until it just begins to simmer. Pour the hot cream over the chocolate and let it sit undisturbed for 2 minutes. Stir slowly from the center outward until the ganache is completely smooth and glossy. Allow it to cool for 5 to 10 minutes until it thickens slightly but remains pourable.

Step 6: Top and Garnish

Drizzle or spread the milk chocolate ganache evenly over the fully set cheesecake layer. Arrange the 3 whole Oreo cookies and 6 Oreo halves across the surface in a pattern of your choice. Return the pan to the refrigerator for 15 to 20 minutes to allow the chocolate topping to set.

Step 7: Slice and Serve

 

Use the parchment paper overhang to lift the entire dessert out of the pan and onto a cutting board. Slice into 9 to 12 bars using a sharp knife. For the cleanest cuts, run the knife blade under hot water and wipe it dry between each slice. Serve immediately or keep refrigerated until ready to serve.