I've played with this recipe over the years and it is now one of my favorites. Whipping the eggs and sugar gives the brownies a lighter texture. For fudgier brownies you can underbake them slightly (24 minutes) but I prefer them at baked for about 28 minutes.
Every time I pull these out of the oven I worry that they are underbaked, however, having been warned in the original version from The Loaves and Fishes cookbook, 22 minutes is all you need. I have cheated and gone up to 24. The brownies seem undercooked at first, but after cooling completely and sitting in the refrigerator for at least 12 hours, they are fudgy and delicious. When I put these up in taste tests with other brownies, they usually win.