Preheat oven to 350 F. Line 24 cupcake tins with liners. Lightly spray insides of liners with cooking spray.
Melt chocolate and water together in a small saucepan. Remove from heat and cool to room temperature.
In a medium bowl, sift together flour, baking soda, and salt.
In a large mixing bowl, cream together butter, brown sugar, and white sugar until fluffy. Beat in vanilla. Add eggs, one at a time, beating well after each. Stir in cooled melted chocolate to integrate
Add dries and buttermilk alternately, beginning and ending with dries, until all is used up.
Spoon batter into prepared cupcake tins. Bake for 20-25 minutes, or until a cake tester comes out clean or the cupcake springs back when touched in the center.Remove from oven and cool completely.