Heat oven to 325°F and line two baking sheets with parchment paper.
Stir coconut, condensed milk, vanilla, and salt in a large bowl until evenly coated.
Whip egg whites in a clean bowl to soft peaks using a hand mixer or whisk.
Fold the whipped whites into the coconut mixture just until combined.
Scoop heaping tablespoons of batter onto the sheets, spacing about an inch apart.
Bake 20–24 minutes, until the edges are deeply golden and tops are lightly toasted.
Cool on the pan for 5 minutes, then transfer to a rack to cool completely.
Melt chocolate in a microwave in short bursts; dip macaroon bottoms and place on parchment to set (optional).