I used the ATK version of buttercream: whip egg yolks in mixer, heat sugar and corn syrup until boiling, then pour the hot sugar mixture into the yolks with the mixer on low WITHOUT hitting either the side of the bowl or the whisk (how you are supposed to do this in practice, I have no idea). You whip that until the bowl is room-temp, then add the other ingredients (butter, salt, etc). Other recipes seem to call for the syrup to hit the side of the bowl. Neither method seems ideal, as when I did hit the bowl or whisk, it cooled and stuck to the bowl, but hitting the eggs seemed to have caused cooked eggs. I doubt there's any fix for it, but what's the right way to do this so I know for the future?