Line three baking sheets with parchment paper or silicone mats.
Sift together your powdered sugar and almond flour, twice. Set aside.
Whisk together the egg whites and granulated sugar in a heatproof bowl over a double boiler. Whisk for about 2 minutes, until the sugar dissolves. You can tell it is ready when you pull the whisk up and touch the mixture with your fingers, you shouldn't feel any granules. Do not let the bowl touch the water or it will cook the eggs
Pour the mixture into the bowl of a stand mixer, fitted with the whisk attachment.
Whisk on low speed for 30 seconds, it should begin to foam. Increase the speed to medium for 2 minutes, until it becomes white and fluffy
Increase the speed to medium-high, it should turn glossy and when you stop the mixer and pull the whisk out, you should have a stiff peak at the end of the whisk which only slightly bends at the end. This is how you know it is ready. This can take 4-5 minutes
Pour in the powdered sugar/almond mixture as well as your vanilla and food coloring
Gently fold them all together. Continue to fold and press the batter against the sides of the bowl. It is ready when it flows like lava from the rubber spatula, and you can make a figure 8 in the air without the batter breaking.
Carefully transfer the batter into a piping bag with a medium circular tip
Pipe out 72 macaron shells, piping at a 90 degree angle. Once they have all been piped out, bang each tray twice on your counter. Use a toothpick to pop any remaining air bubbles.
Let them sit at room temperature for 30 minutes until they form a skin
eat your oven to 325°F/162°C. Bake them one tray at a time for 15-17 minutes. Let them cool completely.
Caramel
Take a small saucepan and place it on your stove over medium heat. Add the sugar ¼ cup at a time, letting the sugar dissolve completely until you add the next ¼ cup.
Stir occasionally until the sugar has completely dissolved and turns a dark amber colour. Turn the heat off.
Add the butter in a piece at a time, be careful as it may sputter! Stir with a heatproof spatula as you add the butter. Stir in the cream, salt, and vanilla. Let cool until it is very thick.
Buttercream
Sift your powdered sugar and set aside.
In a stand mixer with the whisk attachment, whisk the butter for 2 minutes, until smooth
Add in the vanilla extract, caramel and salt. Beat together for 30 seconds
While the mixer is running on a low speed, slowly pour in half of the powdered sugar. Then add in your heavy cream. Add the rest of the sugar.
Increase the speed to medium-high and beat until fluffy, about 3 minutes
Transfer to a piping bag and pipe a dollop on half of the macaron shells. I made a ring around half of the shells, then piped out salted caramel in the middle.
Let the macarons rest overnight in your fridge
Notes
US Cups: I do not include cup measurements for this recipe, as you do need to be precise when making macarons. Aged Egg Whites: If you want to age your egg whites (not a requirement but it can help!), separate your egg whites 24 hours before and place in a bowl in the fridge. Take them out 2 hours before making your macarons so they can come to room temperature.Storage: Keep your macarons in a container in the fridge for up to one week.