1.5 lbs bittersweet chocolate (Ghiradelli, recommended)
2.25 sticks unsalted butter
6 large eggs
1 cup plus 2 tbs packed dark brown sugar
3/4 cups granulated sugar
1.5 tsp vanilla
1/4 tsp baking soda
1/2 tsp cinnamon
1.5 cup flour
Melt the chocolate and butter in a medium saucepan over low heat, stirring occasionally.
Whisk together the sugars, eggs, and vanilla.
Combine chocolate mix with the sugar mix.
In a separate bowl combine dry ingredients (flour, cinnamon and baking soda). Stir gently into the wet mix.
(I recommed to cover the bottom of the pan with greased parchment paper.)
Pour batter into the pan.
Bake in a 13x9 inch pan at 350 degrees farenheit until stick in center comes out with some moist crumbs still stuck on it.
Let cool. Turn cake out onto a clean, flat surface and use a serrated knife to cut them into squares.