1Pour the flour onto a work surface. Make a well in the flour and add the water and salt to the center. Knead with your fingertips to mix. Make sure the water does not splatter everywhere. Form the dough into a smooth ball and cut a cross shape on top. Cover with plastic wrap and refrigerate for at least 30 minutes.
2Remove the butter and dough from the refrigerator at the same time. Place the dough on a floured surface. Flatten each corner with the palm of your hand to form a cross. Roll the cross-shaped dough with a rolling pin, but make sure the center remains thicker.
3Wrap the butter in plastic wrap and flatten it with the palm of your hand until it forms a square. Unwrap the butter and place the butter square in the center of the dough. Fold opposite sides of the dough over the butter.
4Roll out the dough to form a rectangle 3 times longer than it is wide. Fold the dough in three like a letter: that means fold the top third towards the middle, and then fold the bottom third over the middle. Rotate the dough a quarter turn. Roll out the dough again into a rectangle 3 times longer than it is wide. Fold the dough like a letter again and rotate the dough a quarter turn. Cover the dough with plastic wrap and refrigerate for at least 1 hour and 30 minutes.
5Remove the dough from the refrigerator and repeat step 4. Cover the dough with plastic wrap and return it to the refrigerator for another hour and 30 minutes.
6Repeat step 4 again, but this time, roll out and fold over the dough six times instead of two. Cover with plastic wrap and refrigerate for 1 hour.
7Preheat the oven to 210 degrees Celsius (410 degrees Fahrenheit).
8Remove the dough from the refrigerator and place it on a floured surface. Roll the dough out, then cut out two circles that are 24 centimeters in diameter. Place the first circle on a baking sheet covered with a silicone mat or parchment paper.
9In a mixing bowl, combine the almond meal, sugar, softened butter, bitter almond extract, and two eggs.
10Once the almond mixture is well blended, spread it over the center of the pastry, leaving 2 centimeters of space around the edges. Place the second pastry sheet on top and press to seal the edges. Gently draw patterns with a knife. Brush the top of the cake with the beaten egg yolk except for the edges. Baked for 30 minutes, until the pastry has puffed and is golden brown.