Preheat the oven to 325 degrees F and line a baking sheet with parchment paper. Whisk the egg whites, sugar, salt and vanilla in a large bowl until combined; fold in the coconut.
Flatten heaping tablespoonfuls of the coconut mixture into 2-inch disks; place them about 1 inch apart onto the baking sheet. Bake until golden brown around the edges, 20 to 25 minutes. Let cool 10 minutes on the baking sheet, then transfer to a rack to cool completely.
Gently sandwich the macaroons with the vanilla ice cream; freeze until set, at least 15 minutes.