Preheat the oven 350 degrees. Butter the sides and bottom of a 9 x 13 pan. Line the pan with parchment paper.

In a large mixing bowl combine the flour, salt, and cocoa powder.  Set aside.

In a medium saucepan bring a half pan of water to a simmer and set a large mixing bowl on top. 

In the bowl put the coarsely chopped chocolate and the butter.  Stir until completely melted and smooth. 

Remove from heat but leave the bowl on top of the saucepan.  Add in the sugar and brown sugar.  Whisk until completely combined and then remove the bowl from the saucepan.

Add the eggs to the chocolate mix and stir until well combined.  Mix in the vanilla until just combined.

Stir the flour mixture into the chocolate mixture until everything is just combined. 

Pour the batter into the prepared pan and smooth the
top.  Bake for 30 minutes rotating the pan halfway through baking.  Remove from oven and place on a cooling rack until completely cooled.

In a microwave safe bowl heat the chocolate and sweetened condensed milk for 30 seconds.  Mix well.  Put in for additional 15 seconds at a time until it is totally melted. 

Pour over the cooled brownies and spread quickly.  Let cool 2-4 hours or until the ganache becomes firm.

Lift the brownies from the pan using the parchment paper.  Cut
into squares and serve.  Store at room temperature in an air tight container or wrapped in plastic wrap.