While the base is baking, place the cream cheese and sugar in stand or electric mixer
Beat for 2 minutes until light and fluffy.
Add egg and vanilla and beat to combine until the mixture is smooth
Pour mixture onto the baked graham cracker crust and smooth into a single layer. Drop large spoonfuls of Nutella on top of filling and swirl gently with a knife.
Bake 30-35 minutes or until the center only slightly jiggles.
Remove from the oven and cool completely then refrigerate for at least 3 hours or overnight
Once set, remove from pan using the parchment lining and slice into bars.