Step 1: Crafting the Perfect Crust
Crush the Oreo cookies into fine crumbs using a food processor or by placing them in a ziplock bag and crushing them with a rolling pin.
In a mixing bowl, combine the crushed Oreos with espresso powder and melted butter. Mix until well coated.
Press the mixture evenly into a 9-inch springform pan lined with parchment paper.
Place the crust in the freezer while you prepare the filling.
Step 2: Preparing the Creamy Cheesecake Filling
In a large mixing bowl, beat the softened cream cheese, mascarpone cheese, sour cream, cold heavy cream, powdered sugar, vanilla extract, and instant pudding mix using an electric hand mixer.
Mix until the batter is smooth, creamy, and fully combined.
Step 3: Assembling the Tiramisu Layers
Remove the crust from the freezer and spread ⅓ of the cheesecake filling evenly over it.
Quickly dip the ladyfingers in espresso (and Kahlua if using), ensuring they are soaked for less than a second to avoid sogginess.
Arrange the soaked ladyfingers in a single layer over the cheesecake filling.
Spread a thin layer of cheesecake filling over the ladyfingers and smooth it out with a spatula.
Transfer the remaining cheesecake filling to a piping bag with a star tip and pipe decorative dollops over the top.
Step 4: Chilling & Finishing Touches
Cover the cheesecake with plastic wrap and refrigerate for at least 4 hours (or overnight for best results).
Before serving, remove from the pan and generously dust the top with cocoa powder.
