1 ½ cups granulated sugar
5 large egg whites
¾ teaspoon pure vanilla extract
¼ teaspoon salt
4 cups shredded unsweetened dried coconut
6 ounces bittersweet chocolate, chopped, plus one 2-inch chunk of shiny, well-tempered chocolate
Make the cookies:
1. Preheat the oven to 350°F. Line two large baking sheets with silicone baking mats or parchment paper.
2. Whisk together the sugar, egg whites, vanilla, and salt in a large bowl until well combined. Add the coconut and stir until well combined. Drop the batter by packed level tablespoons onto the baking sheets using a medium cookie scoop, leaving an inch between cookies.
3. Bake the cookies for 20 to 25 minutes, or until an even golden brown and dry looking. Let cool completely on the baking sheets on wire racks.
4. To temper the chocolate and dip the macaroons: Melt the chopped chocolate in a bowl set over barely simmering water and stirring frequently (do not let the chocolate go above 120°F.) Add the chunk of well-tempered chocolate. Place the bowl in a cool place and let cool, stirring frequently, to 84°F. Return the bowl to its position over the hot water and stir until it thins slightly and reaches 90°F (but not higher—watch the chocolate carefully at this point).
5. Dip the bottoms of the cooled macaroons into the tempered chocolate, shake off the excess, and place the macaroons chocolate-side down on parchment-lined sheets. Let stand until chocolate sets.
