Preheat the oven to 350°F.

Place the Oreos in a blender and blend them into a fine powder. If necessary, add a few at a time depending on the size of the blender.

In a bowl, combine the powdered Oreos with the remaining crust ingredients. Mix until well combined, then press evenly into a pie tin.

In a medium-sized bowl, beat the cream cheese using an electric mixer until smooth. Add the sugar and egg, and beat until fully incorporated.

In a microwave-safe bowl, combine the chocolate and heavy cream. Heat on 50% power for 30 seconds, then stir. Repeat as needed, ensuring the chocolate is melted and smooth.

Add the melted chocolate, sour cream, Kahlua, espresso, and salt to the cream cheese mixture. Beat until fully combined.

Pour the mixture into the pie crust, leaving about 3/4 inch of space at the top.

Bake the pie in a water bath for 40-45 minutes, or until the top is set but still slightly jiggly. The top will puff up but will settle as it cools.

Remove the pie from the oven and the water bath. Place on a wire rack to cool for about 30 minutes.

Prepare the fudge sauce by combining all the ingredients in a small pot. Heat over medium-high heat for 1-2 minutes, stirring until the sauce thickens and becomes bubbly. Remove from heat and refrigerate to cool completely.

Adjust the oven temperature to 400°F.

In a small bowl, combine all the topping ingredients and stir until well mixed.

Once the cheesecake has cooled, spread the sour cream topping over it using a rubber spatula.

Place the cooled fudge sauce in a pastry bag fitted with a small piping tip, or use a sandwich bag with a small hole cut in the corner. Pipe horizontal lines across the top of the pie. Use a butter knife to drag through the lines lengthwise, creating a decorative design without cutting into the pie.

Bake the pie for 8-10 minutes. Remove and place on a wire rack to cool.

Refrigerate the pie for at least 2 hours before serving.