In a small saucepan, combine the brown sugar, butter and water. Cook and stir over medium heat until sugar is dissolved. Remove from the heat; stir in the chocolate chips until melted and smooth. Transfer to a large bowl; cool slightly.
Add eggs, one at a time, beating well after each addition. Combine the flour, baking soda and salt; gradually add to chocolate mixture and mix well.
Drop by rounded teaspoonfuls onto greased baking sheets. Bake at 350° for 8-10 minutes or until set. Remove to wire racks; flatten slightly. Cool completely.
Combine filling ingredients; spread on the bottoms of half of the cookies; top with remaining cookies. Store in the refrigerator.