Preheat the oven to 325 degrees F (160 degrees C).
Spray a mini muffin tin with vegetable spray and set aside.
In a small bowl, mix together the All-Purpose Flour (2 cup), Kosher Salt (3/4 teaspoon) and Vanilla Powder (1/4 teaspoon). Set aside.
Add the Butter (2 stick) to a large mixing bowl and beat on medium speed with electric mixer to a creamy consistency.
Add the Powdered Confectioners Sugar (1/2 cup) and beat for 1-2 minutes until pale yellow and fluffy.
Add the flour to the butter mixture and beat on low speed until incorporated, scraping down sides of bowl as necessary.
Scoop 1 level tablespoon of dough into each muffin tin. Use floured dough tamper, to tamp the dough into the muffin tin to form little shells. Refrigerate for 10-15 minutes until chilled.
Bake for 10 minutes remove from oven and use your dough tamper again, to press the puffed dough down into the shell.
Bake another 5-8 minutes until golden brown. Allow the shortbread shells to cool in the pan.
Carefully slide a very thin knife between the tart and the pan and remove the shortbread crusts. Cool to room temperature on a wire rack.
While waiting for the crusts to cool, make the passion fruit curd. Slice each Passion Fruit (6) in half.
Scoop the pulp into a blender. On low speed, pulse the blender to separate the seeds from their gelatinous membrane, but not enough to puree the seeds.
Rest a fine mesh sieve over a small bowl and pour the passion fruit into the sieve. Use the back of a spoon to press out the juice, stirring and pressing several times, until you're just left with pulp and seeds in the sieve.
Discard pulp and seeds. You should have about 1/2 cup of passion fruit juice.
In a small saucepan, combine the Large Egg (7), passion fruit juice and Granulated Sugar (1 cup). Stir constantly over medium heat until the sugar dissolves and the sauce thickens enough to coat the back of a spoon.
Remove from heat. Add Salt (1 pinch) and Unsalted Butter (10 tablespoon), one chunk at a time, stirring after each addition until the butter melts.
Place a clean sieve or fine mesh strainer over a small bowl and pour the curd into the strainer. Stir the curd, pushing gently through the sieve (you're removing any egg solids from the curd by straining a second time -- and ensuring a silky smooth texture).
Transfer curd to a bowl or pipe.
When shells are at room temperature, pipe or spoon the passion fruit curd into the shortbread shells.
Top with Kiwifruit (to taste) and Fresh Mint Leaves (to taste) for garnish.
Cover loosely with plastic wrap until ready to serve. Best if served the same day.