Flip the base of a 20cm / 8" springform pan upside down and butter the base. Press a square sheet of baking paper on it and clip the sides of the pan to the base, letting the excess paper hang over. Butter and line the sides of the pan with more baking paper.

Crush the Oreo cookies into fine crumbs and mix with the melted butter until well combined. Press the mixture firmly into the bottom of the prepared pan and chill in the fridge.

In a small bowl, mix the gelatine powder with water and let it sit for about 5 minutes to bloom. Then gently heat it until it dissolves.

In a large bowl, beat the cream cheese and powdered sugar together until smooth. Mix in the Nutella until fully combined.

In another bowl, whip the 1 cup of heavy cream until soft peaks form. Gently fold this into the Nutella mixture. Stir in the dissolved gelatine.

Pour the Nutella filling over the chilled Oreo base, smooth the top, and refrigerate for at least 4 hours, or overnight until set.

When ready to serve, whip the remaining 1/2 cup of heavy cream until stiff peaks form. Spread or pipe this whipped cream on top of the cheesecake.

Drizzle with the warmed Nutella and sprinkle dark chocolate chips and chopped hazelnuts on top for decoration.

Carefully remove the cheesecake from the springform pan, slice into pieces, and enjoy with a scoop of vanilla ice cream if desired.