Heat oven to 350ºF.

Process the sugar for 2-minutes in a food processor. Transfer half the sugar to a small mixing bowl; set aside.

Add the flour and salt to the remaining sugar in the processor. Pulse several times to combine (and aerate). Set aside.

Whisk the egg whites and water in a large metal mixing bowl until the mixture just starts to foam.

Add the cream of tartar and begin whipping on medium speed for 1 minute.

Add the extract and keep whipping on medium speed while very slowly adding the reserved sugar. Whip until all the sugar is incorporated and forms medium peaks.

Add enough of the flour mixture to just dust the top of the foam. Using a rubber spatula, fold it in and repeat until almost all of the flour mixture is incorporated.

Gently spoon the batter into an ungreased tube pan and bake for 35 minutes. Use a long wooden skewer to check for doneness, inserting it halfway between the inner and outer walls of the pan. If the skewer doesn’t come out dry, bake for 5 minutes longer.

Let the cake cool in the pan, upside down, for 2 to 3 hours before removing it from the pan.

Make the lemon ganache. Melt chocolate in the cream until smooth. Stir in the lemon zest and juice. Mix with a immersion blender for the smoothest texture.

Drizzle the lemon ganache over the top of the cake. Garnish cake with fresh berries and mint; if desired.