Preheat your oven to 375 degrees F (190 degrees C).
In a food processer, cake mixer or by hand, cream Unsalted Butter (100 gram), Powdered Confectioners Sugar (50 gram), Salt (1/4 teaspoon) and a few drops of Vanilla Extract (to taste) together about 20 seconds.
Add in All-Purpose Flour (200 gram) and pulse until resembles bread crumbs.
Add in Water (4 tablespoon) while the mixer is running. You may need more if your humidity is dry.
Form it into a dough and divide them into 12 equal portions.
Press the dough into tart tins or a muffin pan. Prick the bottom of the tarts with a fork and refrigerate.
Bake your cooled dough for about 20 minutes and set aside to cool.
In a pot, heat Whole Milk (250 milliliter) on medium low heat until just below boiling.
In a bowl, whisk the All-Purpose Flour (2 tablespoon), Granulated Sugar (5 tablespoon), Corn Starch (1 tablespoon) and the yolks of the Egg (3) until pale in color.
When the milk is warm, temper your egg mixture by adding some milk slowly, while whisking.
Cook the custard on medium low heat, whisking continuously until it thickens. Shut off the heat.
Transfer the cooked custard into a bowl and mix in Vanilla Extract (1 teaspoon).
Wrap the custard with cling wrap and make sure it touches the surfaces of the custard. Otherwise, a skin will form on top while the custard cools. Let it cool in the fridge.
To assemble, remove tart from pan. Loosen custard cream by whisking. Transfer into a piping bag. Pipe cream into the tart.
Top the tarts with your favorite Fresh Fruits (to taste). Serve and enjoy!