Begin by weighing 100 grams of each almond flour, confectioner’s sugar, granulated sugar and egg whites on a kitchen scale.
Combine almond flour, confectioner’s sugar, cardamom and salt in a large bowl. Sift this mixture 3 times, discarding any large pieces left behind.
Next, combine egg whites and 1/2 of the granulated sugar in the bowl of your stand mixer. Make a double boiler with the stand mixer and a small pot of boiling water. Whisk this constantly until the sugar dissolves and the mix becomes frothy, 2 – 3 minutes. Fit the bowl onto the mixer and turn on to medium, adding the remaining granulated sugar slowly. (If you are dying them one color, add the gel food coloring now.) Then turn the speed to high and mix until you achieve stiff peaks.
Add the sifted almond flour mixture to the bowl carefully and mix on low for a few seconds. The mixture will be lumpy and not uniform. Remove from mixer base and fold the batter carefully until you have a uniform mix. (If you are dying the batter two colors – divide into two bowls and add the gel food coloring now.) Continue to fold the batter, twisting in the middle, until it reaches a lava-like consistency. You should be able to draw a figure eight with the batter without it breaking and it will dissolve into the batter within 15 seconds or so.
Add the batter to a piping bag fitted with a large tip. Pipe out macarons using parchment paper or a silicone template. Tamp the tray down a few times to release any air bubbles and allow to dry for 30 minutes. You should be able to lightly touch the tops of them without sticking.
Meanwhile, preheat the oven to 300 degrees. Bake macarons for 13 – 15 minutes, turning the tray halfway through. Remove from oven and allow to cool completely.