Preheat the oven to 325°F (163°C). Line a cookie sheet with parchment paper.
If the shredded coconut is very coarse, pulse it briefly in a blender or food processor until slightly finer and more uniform.
In a mixing bowl, stir together the shredded coconut and powdered sugar until evenly combined.
Add the egg whites and stir until a thick, sticky coconut mixture forms.
Place the mixture over low heat and stir constantly for 2–4 minutes, just until slightly warmed, the sugar begins to dissolve, and the mixture becomes thick and sticky.
Remove from the heat and stir until smooth and fully combined, scraping the sides of the bowl. Let cool for 5–10 minutes, until warm but no longer hot.
Scoop into 18 portions, about 1 to 1 1/2 tablespoons each, and shape into balls or domes. Place on the prepared cookie sheet.
Bake for 15–18 minutes, until the edges are lightly golden and the bottoms are set.
Let the macaroons cool on the pan for 10 minutes, then transfer to a wire rack to cool completely.
