Preheat the oven to 350°F (180°C) and set a kettle of water to boil.

Make the Cookie Crust: Take a 9-inch (23cm) springform (cheesecake) pan and flip over the base. Cover the outside of the pan with heavy-duty, aluminum foil. Place the whole thing in a large roasting pan and set aside.

Crush the wafer cookies to a fine powder in the bowl of a food processor. You can also do this step by hand with a plastic bag and rolling pin.

Pour in the melted butter and mix until evenly combined and press firmly and evenly into the bottom of the springform pan. Place in the fridge to set.

Make the Filling: With a stand mixer fitted with a paddle attachment, beat the cream cheese, granulated sugar, cocoa powder and salt on high speed for about 3-4 minutes, until completely smooth and lump free. Run a spatula around the bowl to make sure the cream cheese is fully mixed.

Pour in the eggs, one at a time, scraping down the sides and bottom of the bowl after each addition.

Add the Nutella, heavy cream and hazelnut liqueur (or vanilla extract) and beat until completely mixed.

Give the batter a few turns with a spatula to make sure everything is evenly mixed and then spread evenly into the prepared springform pan. Place the cheesecake in the roasting pan in the oven.

Carefully pour boiling water from the kettle into the roasting pan until the water comes ⅓ - ½ way up the sides of the cheesecake.

Bake for 50-60 minutes, until the edges of the cheesecake look set but the center still jiggles. (If your cheesecake seems too jiggly then give it an extra 10-15 minutes).

Remove the cheesecake from the water bath and carefully run a thin knife around the edge to release the cake from the pan. Let cool at room temperature for about an hour.

Once completely cool, cover the pan and refrigerate the cheesecake for at least 8 hours (or overnight), until completely cold and set.

When ready to serve, unmold the cheesecake and gently run a palette knife under the cheesecake to loosen it from the pan. Transfer to a serving platter.

Make the Chocolate Ganache: Place the chopped chocolate in a bowl.

In a small saucepan over low heat, warm the cream until it comes to a simmer. Remove from the heat and pour over the chopped chocolate. Let sit without stirring for 5 minutes. (be careful not to over heat the cream here)

After 5 minutes, slowly stir the chocolate and cream together until smooth.

Let cool to a thick but pourable consistency and spread over the cheesecake. Sprinkle with the hazelnuts before letting the ganache set.

Enjoy a big slice with some whipped cream. Store leftovers, covered in the refrigerator for up to 3 days.