Place the pulp and sugar in a small saucepan. Heat it over medium heat, stirring occasionally until it has halved in volume.

Divide the sauce un two and strain one half of it. The half that doesn't have seeds will be for the filling and the other half for the top. Reserve both separately until they have completely cooled down to room temperature.

Add the salt and butter and mix.

Cut baking paper to the size of the base of the pan and also the sides. Stick them in place with vegetable oil that you can spread with a piece of kitchen paper.

Press the base mix onto the base of the pan using the base of a glass and then with your fingers around the edges. Take the pan to the freezer for at least 15 minutes.

Beat the cream cheese with the granulated sugar until it's really soft and homogeneous. Every once in a while stop and scrape down the sides and bottom of the bowl to make sure that everything gets beaten in.

Add the sour cream, vanilla extract, salt and beat again.

Reduce the speed to a minimum and add one egg at a time. You know that you can add the next one when the previous one is incorporated. Finish to incorporate with a spatula if needed.

Pour a third of the mix onto the base and add dollops of the seedless passionfruit sauce. Use a knife or skewer to marble it. Be careful not to disturb the base below. Repeat with the rest of the filling.

Bake the cheesecake in a preheated oven at 180°C / 350°F. When you preheat the oven you want to have a baking pan with water at the bottom layer of your oven so the water preheats, too. If you forget to do it, you can add boiling water. The cheesecake goes on the level above it (not in the water). In this way, the cheesecake still cooks gently but you remove the risk of the water going into the cake.

As soon as it goes into the oven, reduce the heat to 150°C /300°F.

Wait for it to cool down completely and place it in the fridge overnight or for at least 8 hours.

Finish it by spreading the passionfruit sauce with the seeds on top.