In a food processor, place flour, salt, and about half of the butter; pulse a few times to combine.

Add the rest of the butter, pulse a few more times.

Next, add water and process just until combined.

Transfer onto a floured surface and fold a few times to smooth the dough.

Divide into two equal parts and roll each out to about ¼-inch / 1-centimeter thickness.

Fold twice to create a square or a rectangle, cover it with plastic and chill for 1 hour.

In the meantime, prepare cream filling: place milk in a medium saucepan, add vanilla extract and start heating.

In a separate bowl, whisk egg yolks with sugar until pale and fluffy, then add flour and starch, mix until well combined.

When milk comes to a boil, remove from heat.

Pour a small part of hot milk into egg mixture, mix.

Next, transfer egg and milk mixture into the hot saucepan with the remaining milk.

Whisk and continue heating to bring to boil (you’ve just made home-made pudding).

Turn off, cover with plastic foil so it is touching, and cool completely.

Place pudding in the bowl of a stand mixer and start whisking.

Add butter a tablespoon at a time and keep whisking until fluffy.

When dough is done resting, preheat oven to 375℉ / 190 ℃, and line a 9 x 13-inch / 24 x 35-centimeter baking pan with parchment paper.

Roll each dough part out to fit the bottom of the pan.

Bake each dough layer for about 20–25 minutes. Take out and cool.

Transfer cream filling onto one of the dough layers and cover with the second one.

Chill in the fridge for at least 2 hours.

Sprinkle with a generous dose of powdered sugar before serving.