Put the cornflakes and half a of the chocolate hazelnut spread in a bowl and beat to combine. Press the mix into the base of a 4-inch (10 cm) springform tin.
In a separate bowl, beat the cream cheese until smooth, then fold in the remaining chocolate hazelnut spread. Smooth onto the cornflake base, wrap tightly in cling film and freeze overnight.
Remove from the freezer 30 mins before serving, or until you can cut it easily with a sharp knife. Serve in slices with hazelnuts sprinkled over. Will keep in the freezer for up to 1 month.