Preheat oven to 325 degrees F. Position oven rack in center. Butter the bottom and sides of a 9 x 5 inch loaf pan. Line the bottom with parchment paper cut to fit. Butter the paper.
In a medium bowl, combine flour, cocoa powder, baking powder and salt with a whisk to combine. Set aside.
In a large bowl combine butter and sugar. Using a mixer, beat on medium-high speed until the mixture is light in color and fluffy, about 5 minutes. Beat in the eggs, one at a time, beating well after each addition. Mix in the vanilla and mix slightly. Remove bowl from mixer.
Next, using a rubber spatula, gently fold in one-half of the dry ingredients until almost fully incorporated. Next, fold in the milk, followed by the remaining dry ingredients, again until just incorporated. Careful not to mix too vigorously or the cake will be tough.
Pour the batter into the prepared pan and smooth the top with the rubber spatula. Bake the cake until a toothpick inserted into the center comes out clean, about 70 minutes. Carefully watch the time at the end so that the cake does not over bake!
Let the cake cool in the pan on a wire rack for 5 minutes. Place the rack on top of the cooled cake and invert them together. Lift off the pan and peel off the parchment. Turn the cake domed side up and let cool completely on the rack. Cover the cake with a clean, slightly damp kitchen towel so that the outside does not dry out as it cools.
Meanwhile, prepare chocolate ganache topping. Chop chocolate into fine pieces if necessary. In a medium saucepan, measure cream and allow to boil on stove top. Once cream comes to boil, add chocolate to saucepan. Stir with spatula until chocolate is completely dissolved. Add chocolate over pound cake and spread. Allow to cool for about an 1 hour before slicing.