【TART CRUST】Sift powdered sugar. Sift cake flour twice; set aside. Put unsalted butter in a large bowl and cream the butter.

Add the powdered sugar in 2 parts. Mix well each time until creamy. Add an egg yolk and Mix thoroughly until creamy.

Sift almond flour in the bowl and mix well until combined. Add 1/2 Tbsp milk and mix well until combined. Add vanilla oil and mix well.

Add the cake flour all at once. Fold it until the large lumps are formed. Gather the pastry lightly.

Take the dough out of the bowl. Spread plastic wrap on your counter and put the dough on. Knead it lightly until powderiness disappears or it gets smooth. Flatten it into a disk and cover with plastic wrap. Let it sit in a fridge for 3 hours or overnight.

Take the disk out of the fridge and press it lightly to soften. You should leave your disk on a counter for 10-20 mins to soften if it's too firm. Roll it out into 3 mm (0.1'') thick while coating it lightly with bread flour. Wind the pastry around a rolling pin and lift.

Place the pastry on the pan gently and line the pan with it. Trim the edges. Press the side of the pastry against the pan.

Prick bottom of the pastry with a fork. Chill it in a fridge for 30 mins. Preheat an oven to 190℃ / 374 F. 30 mins later, line the chilled pastry with parchment paper. Fill the inside with tart stones.

Bake it at 170℃ / 338F for 15-18 mins until the edges just begin to brown. Remove the tart stones and parchment paper. Bake it for another 15-18 mins until the center of the pastry is golden. Let it cool.

【PISTACHIO CUSTARD】Put pistachio paste, milk and 1 Tbsp granulated sugar into a pot and mix roughly. Pour it into a blender and mix until well combined. Pour it back into the pot and set aside.

Put egg yolks in a bowl. Add granulated sugar and mix it until it turns pale yellow. Add vanilla oil and mix well. Add cake flour and mix it slowly until combined. Set aside.

Warm the milk and pistachio mixture over low-medium heat for 2 mins while stirring. Pour the milk mixture into the egg mixture while stirring. After adding all, continue to stir for 30 sec. Pour it back into the pot.

Cook it over the medium heat while mixing. When bottom of the mixture starts to thicken, turn off the heat and mix well until smooth.

Cook it again over medium heat while mixing. After it becomes heavy like 1st picture below, cook it for another 2 mins. To prevent scorching, mix it while scraping off the cream on the bottom and the corners of the pot. Cook it until large bubbles appear. Turn off the heat and mix it lightly.

Add unsalted butter and mix well until combined. Strain it and then put it in the tart crust and flatten it. Seal the top of the custard with plastic wrap and chill it in a fridge for 2-3 hours.

【STRAWBERRY JELLY】Put 1.5 Tbsp water in a small container. Sprinkle gelatin powder over the water. (You should put water first and then sprinkle gelatin over to prevent unevenness.) Leave it until you use. Cut frozen strawberries into small pieces. Put them into a pot. Add granulated sugar and lemon juice.

Cook it over medium heat for 5-6 mins until it gets softened. Turn off the heat and add the gelatin. Melt the gelatin thoroughly. Add rum and mix well. Strain it and let it cool for about 5 mins.

Pour the strawberry jelly over the top of the chilled custard tart. The scum will come up on the top in about a minute. Place a sheet of paper towel gently on the top and take off the sheet slowly to remove the scum. Chill it in a fridge for 1-2 hours.

【TOPPING】Add granulated sugar to heavy cream and whip it. Add vanilla essence and mix well. Put whipped cream to a piping bag fitted with a star tip. Pipe swirls of whipped cream along the edge of the tart. Top with chopped pistachio. It's all done!!