To make the crust; mix sugar, salt and egg yolk into the flour and add the diced cold butter. Quickly knead a nice cohesive dough. Roll it into a ball, pack in cling film and put a few hours in the fridge to rest for about an hour.
Preheat the oven to 250 degrees Celcius. Grease a cake pan and dust with flour. I use a large, low cake pan (Ø 32 cm) for this cake, but it can also be done in an normal size tin (Ø 24 cm).
Dust the counter with flour and roll out the dough with a roller to about half a centimeter thick. Roll the piece of dough gently over the roller and roll off the cake pan, press gently and cut off the overhanging edges.
For the filling; cut the pumpkin into pieces and remove the seeds(do not peel only wash the pumpkin) and cook for 15 minutes in a little water until the pieces are soft. Drain and let cool for 10 minutes. Put all ingredients together in a food processor, or use a blender to get everything into a smooth paste.
Pour the filling into the (unbaked) crust and put it in the oven. Turn the oven down to 160 degrees Celcius after 10 minutes and let the cake bake for about 40 minutes. Stick a toothpick into the filling if it comes out clean the pie is done. The filling should be creamy and fixed. Let cool and cut into pieces. Serve with whipped cream.