In a small heavy saucepan, combine the butter, brown sugar and water; cook over low heat until butter is melted. Remove from the heat; stir in chips until melted.
Transfer to a large bowl; cool for 10 minutes. Add eggs, one at a time, beating well after each addition. Combine flour, baking soda and salt; gradually add to the chocolate mixture and mix well. Cover and refrigerate for 1 hour or until easy to handle.
Roll into 1-in. balls. Place 2 in. apart on ungreased baking sheets. Bake at 350° for 10-12 minutes or until surface cracks. Remove to wire racks. Immediately place half of a mint candy on each cookie. Let stand until candy begins to melt; spread with a knife.