Preheat your oven to 350 degrees. Prepare your Bundt pan with grease and then cocoa powder, shaking off excess. Set aside.
Using a medium bowl that will withstand the heat from boiling water add your chopped chocolate. Pour boiling water overtop of chopped chocolate and then whisk until smooth. Allow to cool to room temperature.
Add cocoa, flour, nuts, icing or powdered sugar, and salt to a large bowl. Whisk until blended.
Add sugar, brown sugar, and butter to a large mixing bowl. Beat until blended using a stand or electric mixer on medium high speed until light and fluffy, somewhere around 2 minutes.
Place eggs and vanilla in large measuring cup. Beat until totally incorporated.
On low speed add egg mixture. Blend until combined, about another 30 seconds.
Add chocolate mixture. Beat until totally incorporated, about 30 seconds.
Beat or stir in flour mixture jut until combined
Scrape batter into prepared pan, smooth batter, and bake until edges are beginning to pull away from pan, about 45 minutes. Cool upright in pan on wire rack for 1 ½ hours, then invert onto serving plate and cool completely, at least 2 hours.