lemon fluff

zest of 3 lemons
1/2 cup + 4 Tbs fresh squeezed lemon juice
1 1/2 cups sugar--divided
1/2 tsp kosher salt
8 large eggs--separated
8 Tbs  cold unsalted butter-cut into pieces

separate the whites from the yolks of the eggs, placing the yolks in the top of a double boiler and the whites in a clean bowl.  to the yolks add the finely grated zest of 3 lemons, 1 cup sugar, salt, and lemon juice.  whisk together and cook over double boiler until the mixture becomes the consistency of a curd or warm custard.  do not let it boil or simmer.  remove from heat and whisk in the butter. set aside.  meanwhile, beat the whites until they begin to get foamy.  "rain" in the remaining, 1/2 cup sugar and beat until the whites are at a firm but not stiff peak.  When the lemon curd is cool to the touch, but not ice cold, gently fold into the egg whites.  place in individual serving vessels or 1 large bowl.  serve with whipped cream, candied lemon peel, or toasted coconut...or all three!