Preheat oven to 350 degrees F. Line cookie sheets with parchment paper.
In a large bowl stir together flour, coconut and salt. Slowly stir in the sweetened condensed milk and vanilla until all the coconut is evenly coated. Use a cookie scoop to drop 1" balls of dough onto the prepared cookie sheets.
Bake for 12 to 15 minutes in the preheated oven, until coconut is toasted. Remove and allow to cool completely.
In a small bowl add the chocolate chips and butter. Microwave for 30 seconds. Take out the bowl and stir the chocolate. Repeat until the chocolate is melted and creamy. Allow to cool to room temperature.
Dip the bottom of the cookie into the melted chocolate and place on a parchment lined cookie sheet. Refrigerate for about 20 to 30 minutes or until the cookies are firm.