Why Willpower Isn't the Answer
Remove the cue to break the habit.
I've never visited LeBron James' house, but I'm willing to bet his pantry isn't filled with cookies. He probably doesn't waste willpower resisting sweets when life has plenty of temptation without them. Instead, it's easier to never let cookies cross his mind by removing them from his house entirely. I'm a self-proclaimed cookie monster, and even I only ever crave them when I see one.
A habit is made up of a cue, routine, and reward. When trying to break a bad habit, we often focus most on the routine--the physical action we want to stop (eating the cookie). Perhaps a better way to stop a bad habit is to get rid of the cue (seeing the cookie). It's difficult to resist a habit when there are regular reminders for you to partake in it. What's easier is stopping the act before it's even considered by removing any cues.
Sheer willpower in the face of snickerdoodles may fail, but not introducing sweets into your environment, to begin with, is a more reliable way to success. When the distraction is there, the temptation is there. When distraction isn't an option, neither is temptation. Stop trying to break the bad routine. Start looking for ways to remove the cue.