Whisk the egg whites, sugar and condensed milk together in a medium saucepot. Stir in the coconut and flour. Cook this while constantly stirring on medium heat for 3 minutes, to warm up the batter, then increase the mixture to medium high and continue to cook for 5 minutes more, stirring constantly until you feel the batter pulling at the bottom of the pot and the batter is bubbling. If the batter starts to stick or brown as you cook it, reduce the heat slightly.
Transfer the batter to a container to cool uncovered for about an hour, then cover and chill completely before baking. --- could be overnight in fridge
Preheat the oven to 300°F (150°C) and line two baking trays with parchment paper. Use a #40 scoop or 2 tablespoons to drop the batter onto the trays, leaving about 2-inches (5 cm) between them. Bake the cookies for 20 to 25 minutes, until they just begin to brown at the edges. - 7/9/2025: bake at 320F for 15 mins, then raise to 340F for 5 mins --- will harden up when cooling
Allow the macaroons to cool on the trays on racks before removing to store in an airtight container.