Preheat the oven to 300 (150 C).
Prepare 4 baking sheets by lining them with parchment paper.

Finely grind the almond powder and 250 g of powdered sugar, this mixture is called tant pour tant.
Sift this mixture and remove the pieces of almond powder that are too large to pass through the sieve.
Add the remaining powdered sugar, 200 g, and cocoa, then mix well.
Beat the egg whites and whip with sugar 2 to 3 times.
Pour the dry ingredients over the beaten egg whites and mix with a spatula, making sure to scrape the bowl.
 
Macaronade, it’s at this moment that you need to check if you get a ribbon.
Pour the dough into a pastry bag.
Form squares of dough on the parchment paper sheets.
Let it rest for 30 minutes.
Bake for 15 to 20 minutes.
After baking, slide the parchment paper sheets onto a cold work surface and let cool before removing the shells.
In a saucepan, bring the liquid heavy cream to a boil.
In the bottom of a large saucepan, pour 25 g of sugar.
Let it melt, then incorporate 25 g of sugar again and continue in the same way 4 times.
Let it caramelize until the caramel is a nice dark amber color.
Remove the saucepan from the heat.
Being careful with the splatters, add the 32 g of semi-salted butter.
Mix with a spatula, then pour in the cream in several times, mixing.
Return the saucepan to low heat.
Let it cook until the cream is at 108 C (227 F).
Pour into a gratin dish.
Stick a transparent film to the caramel.
Keep it in the refrigerator until it’s cold.
Beat the 145 g of semi-salted butter in pomade for about 8 to 10 minutes, then incorporate the cream in 2 times.
Pour the salted butter caramel cream into a piping bag immediately.
Generously fill half of the shells with ganache.
Store the macarons in the refrigerator for 24 hours before consuming and take them out 30 minutes before tasting.