Put the butter into a saucepan and melt over a low heat. Put the biscuits into a plastic bag and use a rolling pin to crush them to crumbs. Pour the crumbs into a large bowl and then add the melted butter. Mix thoroughly and then press the mixture into the base of a large cake tin or individual mousse rings. Press down firmly to create an even layer for the base of your cheesecake(s). Chill in the fridge for at least 1 hour.
Place the sugar, water and walnuts in a pan and bring to the boil. Bring up to a temperature of 113'C. Once the liquid reaches this temperature, use a slotted spoon to take the walnuts out of the syrup and place on baking parchment to dry.
Place the sunflower oil in a saucepan and heat to a temperature of 140'C. Add the walnuts to the oil and fry until they rise to the surface. This will take around 2 to 3 minutes. Remove the walnuts from the oil, drain in a colander and then place on baking parchment.
Slice the vanilla pod in half lengthways, leaving the tip intact, so that the two halves are still joined together. Holding onto the tip of the pod, scrape out the seeds using the back of a kitchen knife.
Place the soft cheese, icing sugar and vanilla seeds in a bowl and beat with an electric whisk until smooth. Add the cream and continue beating until the mixture is completely combined. Fold in the blueberries and then spoon the mixture on top of the biscuit base, smoothing the surface with the back of a dessert spoon.
Chill in the fridge for a few hours and top with candied walnuts to serve.
«Take care when combining the ingredients: under-beating can lead to a lumpy mixture, over-beating can whip in too much air leading to bubbles and cracking. Use an electric whisk initially and then fold in the cream with a spatula to avoid this.»