Preheat the oven to 350°F (177°C). Wrap 9-inch springform pan with double layer of aluminum foil.
In a small food processor, process the cookies until fine crumbs. Add melted butter and pulse until well combined.
Press onto the bottom of prepared cake pan. Bake for 10 minutes.
In a microwave-safe bowl, melt the chocolate chips in 30-second increments at 50% power until nice and smooth.
In a large mixing bowl with whisk attachment, beat cream cheese until fluffy.
Add sweetened condensed milk and beat until smooth.
Add eggs, one at a time, beating well after each one.
Add sour cream and give another good stir.
Then stir in flour, espresso powder, vanilla extract and salt.
Add melted chocolate. Mix until smooth, 1-2 minutes.
Pour the batter into the prepared crust.
Set the cake pan in a roasting pan and pour hot water up to half way of cheesecake pan. (Alternatively, if you don’t have large enough pan, you can fill another baking pan with hot water and place it on the bottom rack below the cheesecake pan.)
Bake for 55-60 minutes, or until the center is almost to set. Open the oven door ajar and cool for an hour.
Remove the cake on wire rack, and then in 10 minutes carefully run a knife around the edge of the pan. Cool until room temperature, and then refrigerate for at least 2-3 hours, or preferably overnight.
To make the ganache, heat heavy whipping cream in the microwave until hot.
Pour it over chopped chocolate. Let it sit for 2 minutes and then stir until smooth. Immediately pour the ganache over the cheesecake. Chill until set and serve.