Preheat your oven to 350°F and line a 9" springform pan with parchment paper.

For the crust, combine Oreos and instant espresso powder in a food processor. Pulse until finely ground. Add melted butter and pulse until well mixed. Press the mixture firmly into the bottom of the springform pan and bake for 10 minutes. Set aside to cool.

Lower the oven temperature to 320°F. Place a large roasting pan on the middle rack and fill it with hot water to about 1" depth. Close the oven door.

In a mixer, beat the cream cheese, room temperature butter, and granulated sugar on low until smooth. Scrape the bowl as needed. Add eggs one at a time, ensuring each is fully incorporated. Mix in vanilla extract, 6 tablespoons of prepared espresso, and flour. Pour half of the cheesecake filling into the cooled crust.

Dip the ladyfingers in the remaining espresso and arrange them in a single layer over the filling. Pour the rest of the cheesecake filling over the ladyfingers and smooth the top.

Place the springform pan into a 10" cake pan, then put this into the water bath. The water should reach halfway up the cake pan. Bake for 1 hour.

Turn off the oven and let the cheesecake cool inside with the door slightly open for 1 hour. Remove the cheesecake, run a knife around the edge of the pan, and let it cool completely on the counter.

Refrigerate the cheesecake, uncovered, for at least 6 hours or overnight to set. Do not remove the springform pan.

For the whipped topping, beat the heavy cream until stiff peaks form. In another bowl, mix the cream cheese, milk, and instant pudding until smooth. Fold in the whipped cream until fully combined.

Remove the springform pan and transfer the cheesecake to a serving platter. Use a piping bag with a large tip (like Wilton 2A) to pipe large dots of the whipped topping onto the cheesecake. Dust with cocoa powder and keep chilled until ready to serve.