Garnish: powdered sugar,strawberries or raspberries, mint leaves
Preheat oven to 325 degrees. Spray an 8×8-inch baking dish with nonstick spray.
Separate eggs and place yolks in a large bowl of an electric mixer. Add in sugar and water & beat until creamy & light.
Continue beating as you add in melted butter, salt and vanilla. Mix until well incorporated and batter is light & fluffy.
In a small bowl, combine flour and cocoa powder. Add to batter a little at a time, mixing well after each addition. Continue mixing and add milk, warmed just enough so that it doesn’t cause the butter to gel. Batter will be thin.
Beat egg whites and vinegar in electric mixer until they form stiff peaks. Fold a little into chocolate mixture. Then fold chocolate mixture into the remaining egg whites. Combine all together and fold gently.
Pour into prepared pan. Bake 60-65 minutes or until top edges look set and the center jiggles just slightly.
Place on wire rack to cool completely. Once cool, cut into squares. I put mine in the refrigerator for a bit to make it easier to cut. Garnish with powdered sugar and fresh berries.