Adjust your oven rack to a lower, middle position. Preheat oven to 325 degrees.

Grease and flour a 8 1/2 x 4 1/2 in loaf pan.

In a small bowl combine flour and salt.

In a medium bowl, place the cocoa powder and chocolate. Pour the boiling water over the chocolate and cocoa and stir until the chocolate is melted. Let cool for 5 minutes.

With an electric mixer, beat the butter, sugars, vanilla, and the chocolate mixture on medium-high until fluffy, about 2-3 minutes. Add the eggs one at a time and beat until combined.

Reduce speed of mixer and add flour in three additions. Scrape bowl as needed.

Give the mixture a final stir by hand with a rubber spatula. Pour finished batter into prepared pan.  Gently tap the pan on counter to release any air bubbles.

Bake about an hour, rotating pan after 30 minutes. Use a toothpick and insert in center of loaf. When it comes out clean, the cake is done.

Let cool in pan for 10 minutes. Place on wire rack and let cool completely before serving.