Combine the egg whites with the powdered egg whites by stirring in the powdered egg whites in a slow cascading motion with a whisk.
Grind the sugar in a coffee grinder until very fine.
Combine the almond flour with the confectioners’ sugar and then mix in a Robot Coupe for 30 seconds; pass through a drum sieve.
Whip the egg whites on high speed; when they have reached medium peaks, sprinkle in the ground sugar, and then whip to stiff peaks. Add a few drops of purple food coloring.
Fold the meringue into the flour mixture until smooth; do not overmix (it will become very loose).
Pour into a piping bag fitted with a #2 tip.
Pipe the macarons onto a sheet pan lined with a nonstick rubber mat, leaving at least a 2.5-cm/1-in space between each. The diameter of the macaron should be about 5mm/.2in. Let them air-dry for 15 minutes.
Meanwhile, turn a convection oven on to 149°C/300°F and set to fan speed 2. Bake the macarons for 7 minutes, then turn off the oven and let the macarons dry for 3 more minutes
Cool at room temperature. Fill with the violet ganache. Reserve frozen for up to three months or refrigerated for up to ten days.