Before you start, make sure that all your ingredients are at room temperature (including the cream and Skyr for the mousse).

For the pistachio pastry

1. Use a mixer to beat the margarine until soft using the K-attachment on your food processor or the dough kneader attachment on your hand mixer. Add the egg to it.
2. Add the finely ground pistachios (finely grind them using a chopper or blender). Mix again.
3. In a separate mixing bowl, mix the flour with the Zùsto and salt. Now add the flour and Zùsto mixture in to the rest, one spoon at a time.
4. Knead (with a food processor or your hands) into a dough ball. Wrap the dough in cling film and leave to rest in the fridge for 2 hours.
5. Grease the springform tin with margarine or butter and preheat the oven to 180°C.
6. Generously dust your work surface and rolling pin with lots of flour. Remove the dough ball from the refrigerator and roll out the dough. Carefully place it in your springform tin. You will have quite a bit of dough left over (approximately 1/3). Can’t get your dough to neatly fit in the tin? Don’t worry, the sticky stuff works wonders. Take pieces of the dough and “stick and knead” it to the rest. Make sure you have a raised edge of about 3 cm. Cut away the excess dough.

For the pistachio frangipane

1. Blend the margarine until soft. Add the egg.
2. Mix the chopped pistachios first in a separate mixing bowl with the Zùsto and then add them to the rest.
3. Continue mixing until everything is fully blended.
4. Pour the frangipane batter over the dough and bake for +/-20 min in the preheated oven (or until the edges turn golden brown).

For the raspberry mousse

1. Put the raspberries together with the Zùsto in a saucepan and warm over a medium-high heat. Let it simmer until the raspberries begin to fall apart. When all the raspberries have fallen apart, pass them through a sieve (leaving the seeds behind and giving you a smooth coulis)
2. Add the sachet of agar agar and reheat until it begins to boil. Allow to boil for 2 minutes (it’s only at this point that the agar will start working). Set aside for a moment while you prepare the rest.
3. Whip the cream until it becomes whipped cream and add the vanilla extract. Add the Skyr and mix again briefly until you have a smooth batter.
4. Make sure the raspberry coulis is cooled, but not completely (as the agar will start to make it set when it’s at room temperature). Add the coulis to the batter drop by drop as you continue to mix. Have you ended up with chunks and lumps? If so, your agar has probably already done it’s thing. Don’t worry, just run the hand blender through it again or put everything in the blender.
5. Pour the mousse over the pistachio frangipane and continue to let it set in the refrigerator for at least 4 hours (or overnight).