No-fail recipes are probably the hardest things to find. There are millions of recipes online, a number of variables can affect the results (elevation, humidity, etc.), and your own personal expectations may not match up with the recipe (should donuts be cake-y or bread-y?). So if I find one that works for me, I will be loyal to the source as long as nothing else fails me.
This is my long-winded way of saying: I trust Emma.
I've made her brownies twice in the last 4 weeks (simply omitting the Snickers). That first time was for a dinner party, so I had to make them a second time so I wouldn't have to share.