Pre-heat the oven to 325. Line an 8 x 8 baking pan with parchment paper and spray the parchment paper well with cooking spray. Combine the chocolate and butter in a large mixing bowl. Get a small pot filled halfway with water on the stove and bring it to a gentle simmer over medium heat. Set the bowl over the simmer water to let the chocolate and butter melt together. Stir it all with a heat proof spatula until it is completely smooth and shiny. Take the bowl off of the heat and let it cool for a minute.

Whisk the sugar into the chocolate mixture, followed by the vanilla, egg yolks, flour, salt and cinnamon just until it is all combined. It it will incredibly thick and a little grainy but don't worry. Then use a hand mixer to whip up the egg whites until they become doubled in size but not to the point of it forming stiff peaks. Use a spatula to fold the egg whites into the rest of the batter just until it disappears. Transfer the batter into the prepared baking dish and smooth it out to be even.

Bake the brownies for about 30 minutes, until it looks dull on top and a toothpick comes out cleanly. Then let them cool completely before cutting them into 16 equal squares. Enjoy!