Place the cream cheese in a medium bowl and, using a handheld electric mixer, beat it on high speed until light and fluffy. Add the sugar and beat until well combined, scraping down the bottom and sides of the bowl every so often.
Add the hazelnut spread, cornstarch and vanilla and beat again until smooth.
Add the eggs one at a time, beating well between additions. Add the cream and beat on low speed until well combined.
Chop the Ferrero Rochers into small, medium and large-sized pieces for variety, and then, using a spatula, gently fold the pieces into the cheesecake filling.
Pour the filling on top of the crust in the cheesecake pan and use the spatula to spread it evenly overtop of the crust. Place the cheesecake pan on a rimmed baking sheet. (This ensures there are no leaks and makes it easier to remove from the oven.) Bake the cheesecake on the centre rack of the oven until it is starting to brown around the edges, about 1 ½ hours. After baking, it should be wiggly in the centre, but not wet.
Remove the cheesecake from the oven and let it cool in the pan at room temperature. Once it is cool, cover it tightly with plastic wrap and refrigerate for 24 hours to set.