This is the only brownie recipe I trust.
I have done this a few dozen times, at least.
By far, the only recipe that I blindly trust.
I switch the water for brewed coffee (to enhance the chocolate flavor) and the impalpable sugar for 3/4 cup of brown sugar and 1/4 cup of starch (to avoid being overly sweet). It works for me!
Also, trust the process: the longer you wait for it to cool down, the better it gets!