2) Eat a little each day so it doesn't have a big caloric impact and risk it causing you to revert back to old behaviors
This one is best of the three I think (to save your dog hehe). Just because you cheat on your diet doesn't mean you should completely sabotage it. Some people get this mentality of "Well I already broke my diet, so I might as well eat a whole pizza and a bucket of chicken wings because my diet is just ruined for the day." Your diet is only ruined a little bit but if you gorge yourself, obviously you'll gain more weight than if you just cheated a little bit.
If I were you, I'd just plan the apple pie into your diet and subtract that from your caloric goals. So if you eat a slice of apple pie, subtract out an equal amount of calories from somewhere else. Obviously apple pie is full of sugar and sugar isn't really the best way to fill your diet because it might just make you more hungry, but everybody has these situations where they have to cheat. Eventually you'll have to go to a party or restaurant with friends and eat out etc.