In a mixer add butter, brown sugar and mix until light and fluffy. Add eggs and vanilla and beat until thoroughly mixed. Add flour, baking soda and salt and mix well. Refrigerate for about an hour.
In a saucepan over medium heat, add the chopped dates, ½ cup of sugar, water and melted chocolate and stir constantly until mixture is thick and bubbly. Remove from heat and stir in chopped walnuts or pecans.