Preheat oven to 350°F. Grease a standard bundt pan generously with butter and “flour” the inside of the pan with a few tablespoons of cocoa powder. Set aside.
In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder and salt.
Melt the butter in a small saucepan or in the microwave in a microwave safe bowl at medium heat. Once the butter is melted, stir in the chopped chocolate until melted and combined. (If the chocolate doesn’t melt, place in the microwave for 20 seconds at 50% power and stir again).
Allow the chocolate mixture to cool for five minutes.
In a large bowl, combine the melted chocolate mixture, eggs, milk and vanilla extract. Whisk to combine.
Add half of the dry ingredients, stirring just until combined.
Whisk in the water and then finally, add the remaining dry ingredients and stir just until combined.
Transfer the batter to the prepared bundt pan and bake until an inserted toothpick comes out with a few moist crumbs, about 45 to 50 minutes.
Remove from the oven and allow to cool for 10 minutes.
Run a knife or spatula around the edge of the cake to loosen and then invert onto a wire rack. Let cake cool completely.
Serve with powdered sugar, whipped cream or a simple glaze.