Heat oven to 375 degrees F. Grease and flour two 9-inch round baking pans.
Cake
In a small saucepan, combine mint-chocolate chips and 1/4 cup of the water. Cook over medium heat, stirring constantly, until chips are melted and mixture is smooth; Cool for 10 minutes.
In medium bowl, combine flour, salt, baking soda, and baking powder; set aside.
In a large bowl, combine brown sugar and butter; beat until creamy. Add eggs, 1 at a time, beating well after each addition. Blend in chocolate mixture. Gradually beat in flour mixture alternately with remaining 1 cup of water. Pour into prepared baking pans.
Bake for 25 to 30 minutes, or until cakes test done. Cool completely on wire racks.
Fill and frost with Chocolate Mint Frosting. Garnish as desired.
Chocolate Mint Frosting
Combine over hot (not boiling) water, the mint-chocolate chips and butter; stir until chips are melted and mixture is smooth. Stir in vanilla extract and salt. Transfer to a large bowl. Gradually beat in the confectioners' sugar alternately with milk; beat until smooth. (if necessary add more milk until desired consistency is reached.
Garnishes
Use chocolate curls and grated chocolate on top of the cake. Form a ring of grated chocolate pieces around the outside edge and use the curls in the center.
To make chocolate leaves, select several small leaves, wash and dry them and paint one side of them with melted chocolate. Chill until firm and peel the leaf off the chilled chocolate. Use as garnish.