Step 1

With an electric hand mixer cream room temperature butter with the sugar for a few minutes until light and fluffy.

Step 2

Mix in the eggs and vanilla just until combined.

Step 3

Mix flour, salt, and baking soda together, then add the mixture to the wet ingredients. Fold them together with the help of a rubber spatula.

Step 4

Prepare 2-3 baking pans with parchment paper. Divide the dough into 12 equal balls (using a digital scale is handy or use an ice cream scopper) and place them onto the parchment paper, leaving enough space between them to be able to spread.

Step 5

Chill the cookie dough for an hour.

Step 6

Pre-heat oven to 175 C / 347°F (no fan). After one hour of chilling time, bake the cookies for 15 minutes.

Step 7

Let the vanilla cookies rest for a few minutes, then carefully remove them from the parchment and cool them on a cooling rack. The cookies will further set as they cool.

Step 8

In a large enough bowl, with the help of a hand whisk, whisk together sugar and egg yolk until slightly fluffy for about 1-2 minutes.

Step 9

Whisk in the corn starch, flour, and vanilla with until thoroughly incorporated and have a smooth paste.

Step 10

Bring milk to boil in a saucepan on medium heat then remove it as soon as it starts simmering. Make sure it is simmering but not crazy boiling.

Step 11

Pour the warm milk over the egg yolk mixture slowly while whisking vigorously with a hand whisk. This stage is effectively tempering the egg yolks and the mixture should already start to slightly thicken.

Step 12

Pour the mixture back into the saucepan and cook on medium heat for a few minutes until it thickens. Concretely it is approximately 1 min after the first boil. It might get lumpy first, don't worry just keep whisking and the cream will get smooth and glossy. It's worth to keep a good quality (so that the milk won't burn in it) small/medium sized saucepan for making pastry cream only.

Step 13

If in doubt, strain the pastry cream for a lump free, creamy end result.

Step 14

Add in room temperature soft butter and mix with a Rubber spatula until completely incorporated. It is worth to add the butter in 3 stages and mix well after each addition.

Step 15

Pastry cream needs to completely cool before using it. Place the cream into a shallow tin and cover the entire surface with plastic wrap to avoid skin forming on top. Refrigerate until using it.

Step 16

Please note that the caramelized sugar, after a few hours, will start to melt on top of the cookies so only make the brûlée top right before serving the cookies. Also, the pastry cream, if stayed too long, might make the cookies moist, so the entire assemble should be applied straight before serving.

Step 17

When the cookies are no longer hot and the pastry cream cooled to room temperature, spread the pastry cream evenly on top of the cookies.

Step 18

To make the brûlée top; sprinkle the top of the pastry cream with a thick layer of demerara sugar, then caramelize it in a few seconds with a blow torch.

Step 19

Store any leftover cookies refrigerated in an air-tight container for 2-3 days. Sprinkle with some more sugar and apply the blow torch again before serving.