Preheat the oven 325°F. Line 2 large baking sheets with parchment paper and set aside.
In a large bowl combine the sweetened condensed milk and vanilla extract. Mix with a silicone spatula until combined. Add the coconut, lime zest, and lime juice and stir with spatula until combined. Set aside while you beat the egg whites.
In the bowl of an electric mixer fitted with a whisk attachment, beat the egg whites and salt on medium/high speed until stiff peaks form, about 3-4 minutes. Be careful not to overbeat the egg whites. Fold the egg whites into the coconut/lime mixture until no white streaks remain.
Using a small cookie scoop, scoop coconut/lime balls onto prepared baking sheet, leaving about 1 1/2 inches of space between each coconut/lime ball.
Place baking sheet in the oven. Bake, rotating halfway through for 25-30 minutes or until macaroons are light golden brown on top and the underside is tan.
Remove macaroons from the oven and allow them to cool for about 5 minutes or so, then transfer them to a cooling rack to cool completely.
Makes about 45 small macaroons
Adapted from:
Fine Cooking