Preheat the oven to 350°F (175°C).

In a mixing bowl, combine the flour and sea salt. Add the diced butter and mix until it resembles coarse crumbs.

Stir in powdered sugar. In a separate bowl, mix the egg yolk and cold water, then gradually add it to the flour mixture until dough comes together.

Wrap the dough in plastic wrap and chill for about 30 minutes.

Roll out the chilled dough on a floured surface and fit it into tart pans. Poke holes in the bottoms with a fork.

Bake for 10-12 minutes or until lightly golden. Allow to cool and remove from pans.

In a food processor, combine the pistachios and sugar, and pulse until finely ground.

In a saucepan over medium heat, whisk together the heavy cream, vanilla, egg, cornstarch, and pistachio mixture until smooth. Cook until thickened, about 5 minutes, stirring constantly.

Spoon the pistachio cream into each tart shell and top with fresh raspberries. Optionally sprinkle powdered sugar on top.

Chill the tarts for about 30 minutes before serving.