Preheat the oven at 350 F and line the base and sides of a 13 x 9 baking pan with parchment paper.
Put the chocolate and the butter in to a metal bowl and place it on a pot of simmering water, making sure the water is not touching the bottom of the bowl. Melt the chocolate and the butter slowly mixing from time to time with a rubber spatula. Careful not to get water in to the bowl. Set aside to cool off.
Beat the eggs and sugar well with the aid of a kitchen aid. I like to use a rubber spatula attachment. Add the vanilla extract. Slowly add the chocolate and butter. Fold in the flour, cocoa powder and salt by hand making sure to incorporate all and mix gently until uniform in color.
Pour in to the lined baking pan and cook in the oven for 25 minutes. The center should be still a little soft and gooey. Place on a rack to cool off. Cut in 48 squares.
You can add walnuts, coconuts, dried cherry hazelnuts, white chocolate chips, butterscotch , a shot of espresso, a hot of rum, or even half a glass of red wine! YUM YUM YUM