In a saucepan bring the water with butter and salt to the boil. Sift in flour and stir until smooth and it forms a ball in the pan.
Transfer mixture to a bowl and add one egg at a time, stirring well after each addition. Stir in baking powder and sugar.
Grease 3 (26cm) springform tins and fill each with 1/3 of the mixture. Smooth with a spatula and bake for 15 minutes. Don't open the oven door while baking. Take the pastry bases out of the oven and let cool. (If you don't have 3 springform tins, you can also bake one base after the other.)
For the filling:
Soak half of the gelatine as instructed on the packet.
In a saucepan heat raspberries and cook until they fall apart. Add half of the caster sugar and stir in liquid gelatin. Stir until dissolved then set to the side to let cool, stirring often.
In a bowl beat cream until soft peaks form. Gradually beat in the remaining caster sugar and vanilla sugar until stiff. Heat up the remaining gelatine until is it liquid then let cool down a little. Quickly stir into the whipped cream.
Line a springform tin with cling film. Insert one pastry base and spread 1/2 of the raspberry mixture and 1/2 of the whipped cream on top. Add the second base and cover with the remaining raspberry mixture and whipped cream. Top with the third pastry base. Make sure that the wavy side of the pastry is facing up. Cover the torte and place into the fridge for 3 to 4 hours until the filling is firm. Bevore serving, take out of the springform tin and dust with icing sugar.