This is the exact recipe my mom used as we grew up. I even have it posted at my blog as coming from her, because I don't know the original recipe's author, since my copy of it is hand written.
So I made this for a bake sale at our yard sale, and these were hot sellers! These are rich, dense, and fudgy! I made them in an 8x8 pan, baked for 40-50 minutes, checkig it. Cut into 9 big squares.
This is my idea of the ultimate brownie. I made it exactly as the recipe was written and they turned out perfect. I wouldn't even add more sweetness - they were chewy, fudgy, and moist - even when left out uncovered overnight.
I think my family still prefers the Dump Bars (also on this site) because of the chocolate chips but I found those to be on the dry side.
CHEWY, FUDGY FLOURLESS CHOCOLATE COOKIES
3 cups powdered sugar
⅔ cup Dutch processed cocoa powder
¼ tsp. salt
3 large egg whites, room temperature
1 tablespoon vanilla extract
1½ cups semi-sweet chocolate chips
Line two baking sheets with parchment paper and spray with nonstick spray.
In a large bowl, whisk together powder sugar, salt, and cocoa powder. Stir in egg whites and vanilla extract until the batter is completely moistened. It will be very thick. Gently stir in the chocolate chips.
Spoon the batter on the sprayed parchment lined sheets, 12 mounds per sheet. Preheat the oven to 350º. Let the cookie sheets rest for 30 minutes before baking. The cookies will almost develop a crust on them. Bake for 10-12 minutes until tops are glossy and lightly cracked.
Let the cookies cool for a few minutes on the baking sheet before gently transferring them to a cooling rack to finish cooling.