Preheat oven to 325 degrees. Grease and flour a 10" bundt pan.
In a medium bowl, combine flour, baking powder and baking soda. Set aside.
In a small saucepan, bring water and coffee granules to a boil. Remove from heat and stir in baking chocolate until smooth.
In a large bowl, beat sugar and butter until creamy. Continue to beat while adding in vanilla and eggs. Beat for 5 minutes. Turn mixer to lower speed and add in flour mixture alternately with chocolate-coffee mixture.
Pour into prepared bundt pan and place in oven for 50-60 minutes. Cake is done when wooden toothpick inserted in center comes out clean. Cool in pan for half an hour, remove and let cool completely on wire rack. Place on serving plate and drizzle with chocolate glaze.
While cake is baking, prepare glaze.
In small saucepan, melt chocolate with butter over low heat. Stir until smooth. Remove from heat, stir in vanilla. Alternately stir in confectioner's sugar and water until desired glaze consistency.