Whip the butter until creamy. Scrape the bowl and incorporate the sugar.
Add the egg, salt and vanilla. Switch to a kneading hook or wooden spoon. Stir the flour in the mixture, adding one third at a time.
Use your hands to knead the dough into a ball - make sure it does not stick to your hands. If it does, add more flour. If it is too dry to combine into a smooth dough, start again and use more of your butter or add a second egg. Chill the dough for at least one hour, better overnight.
Roll out on parchment paper, then flip onto a well-buttered Tarte from another round baking tin. Carefully press the dough into the form. Use a fork to ensure hot air can escape from underneath the dough.
Place parchment paper on top, fill with dried peas or beans to blind bake in the oven. Bake at 180C for 17min. Check for browning on the crust.
Once they start to disintegrate, add the lime zest and sugar amount depending on how sweet you like it. Let it boil until there are no more raspberry lumps.
Dissolve the cornflour in the water, make sure there are no lumps either. Add the cornflour mixture into the raspberries.
Stir, let boil until it feels jam. Remove from heat, fill raspberries into a separate bowl, and let cool down for 30 minutes.
Fill into the tarte case once removed from its tin and cooled down. Chill in the fridge for at least an hour.
In a pan add cream and bring it to a boil.
Pour over white chocolate. Let sit for 2-3 min. Stir until completely smooth mixture - if lumps remain, place bowl over water bath and keep stirring.
If preferred, add a couple of drops of the white food coloring and stir until completely incorporated.
Let cool until consistency is about that of honey. Pour over cooled raspberry filling in the tarte case. Place back in fridge.
Arrange on top of the hardened white chocolate ganache according to personal taste.
Wait to do this until the ganache is thickened to the touch. For garnishing, cut the fruit in slices.