I made them again today.
I will try my best to NOT eat the whole pan, this time.
FYI, I tried using two whole eggs in the batter, instead of one egg and two whites. It worked just fine, and I didn't notice a big difference in the brownies (although the two-egg version may have been slightly fudgier).
I also tried sprinkling a little bit of Fleur de Sel (a.k.a. wicked expensive sea salt) over the batter just before baking. Still haven't tried those Sea Salt Brownies from Trader Joe's, but I'm guessing they must be something similar. The hubby was a bit dubious about salty brownies, but it works - kind of like those Sea Salt Caramels that are suddenly everywhere.
Next time I make these, I want to try baking the batter in mini-muffin pans - to approximate those Two Bite Brownies sold in chichi grocery stores. Stay tuned...