Fleur de Sel Caramel Macarons
For the macarons shells:
200 gr powdered sugar
110 gr almond flour
90 gr egg whites (preferably aged 3-4 days in the fridge in a lidded container or aged in microwave at power 3 for 15 seconds)
50 gr granulated sugar
Sift the almond flour and powdered sugar together through a fine mesh sieve.
In a stand mixer fitted with the whisk attachment, whip the egg whites to a foam (think bubble bath foam), gradually adding the sugar until you obtain a glossy meringue (think shaving cream). Do not overbeat your meringue or it will be too dry.
Add the nuts and powdered sugar to the meringue, give it a quick fold to break some of the air and then fold the mass carefully until you obtain a batter that falls back on itself after counting to 10. Give quick strokes at first to break the mass and then slow down. The whole process should not take more than 50 strokes (i've found 40 to be the magic number). Test a small amount on a plate: if the top flattens on its own, you are good to go. If there is a small beak, give the batter a couple more turns.
Fill a pastry bag fitted with a plain tip (Ateco #807 or #809) with the batter and pipe small rounds onto parchment paper or silicone mat lined baking sheets. Let the macarons sit out for 30 minutes to an hour to dry their shells.
When you are ready to bake, preheat the oven to 280F.
Bake the macarons for 15 to 20 minutes, depending on their size. Let cool.
Once baked and if you are not using them right away, store the shells in an airtight container out of the fridge for a couple of days or in the freezer for up to 2 weeks.
For the fleur de sel caramel filling:
125 gr heavy cream
175 gr granulated sugar
5 gr fleur de sel
175 gr butter, cut into small cubes
Place heavy cream in a small saucepan and heat over medium heat. Cook cream until it just begins to boil, then remove from heat.
While the cream is heating pour sugar into a heavy bottom pan and place over cook stirring occasionally so it doesn't burn and caramelizes evenly. Once the sugar reaches a dark copper color, remove from heat and pour in hot cream, continuing to stir with a spatula.
Let mixture cool to around 115F. Add fleur de sel and butter, a few cubes at a time, while continuing to stir the caramel. Once all the butter has been incorporated, pour the caramel into a shallow container and let cool in the fridge. Once cooled, beat the mixture until light, shiny and smooth.
Fill the macarons and let them mature in the fridge for at least 24 hours prior to eating them. Let return to room temperature before serving.
Yields about 30 small macarons.