1In a bowl, mix the butter and 300 grams of powdered sugar until it is quite creamy.
2Add 2 eggs, the vanilla extract, a pinch of salt, the flour, and mix to get a homogeneous dough.
3Wrap it with plastic film and refrigerate for at least 2 hours.
4Preheat oven to 180 degrees Celsius.
5Remove the dough from the refrigerator and wait 10 minutes before working with it so as not to break it.
6Divide in 3, and roll out the first third on a lightly floured work surface until it is 3 to 4 millimeters thick.
7Cut out the shapes with a cookie cutter and place them on a baking sheet lined with parchment paper. Make sure to have as many solid cookies as cookies with cutouts.
8Bake for 12 minutes until lightly browned.
9Proceed in the same fashion with the remaining dough.
10Prepare a dish with 4 tablespoons of powdered sugar. Right out of the oven, coat the cutout cookies, and let them cool down.
11Coat the solid cookies with the jam when they begin to cool down.
12Then paste 2 cookies together (the jam will make the cookies 2 parts hold together)
13Using the same recipe you can make around fifty shortbread cookies depending on the size of the cookie cutter that you use.
14Beat the egg white with a fork, gradually adding 280 grams of powdered sugar, and a few drops of lemon juice to get the desired texture, thick enough that it does not run off the cake.
15You can use a pastry bag with a small nozzle to ice the shortbread cookies.
16First, delimit the edges of the cake and then fill up with the icing.
17Let stand for 20/25 minutes.