Pre-heat your oven to 160C Fan/350F/Gas Mark 4 and grease and line a 12" x 9" traybake tin
To make the cheesecake filling mix together the full fat cream cheese, caster sugar, egg and Nutella with a hand whisk or electric hand whisk until smooth. Set aside
Melt the butter with the golden caster sugar in a pan on a low heat
Once the butter has melted, take the pan off the heat and add the white chocolate. Leave it for a couple of minutes to melt, then stir together. Leave the mixture to cool for 5 minutes
Break the eggs into a bowl and add them to the mixture, keep whisking as you pour them in to make sure the mixture doesn't cook the eggs. Then stir in the vanilla extract
Add the flour and whisk it in
Pour the blondie mixture into the traybake tin, then add the cheesecake mixture on top in spoonfuls all over
Using a butter knife, swirl the mixture around to create the swirl
Bake for 30-35 minutes, or until they are golden brown all over. Using a skewer inserted in the centre doesn’t give a clear indication that they are done because blondies are meant to be gooey and almost a little under cooked. It is better to use a cocktail stick, it should have several moist crumbs on it but not be wet. Blondies are the white chocolate version of brownies and they are not like cake. They will also set more as they cool down
Leave it to cool completely before cutting into squares
Store in the fridge and eat them within 3 days