These are my opinions. Read as I run out of colors! Feel free to disagree, and definitely feel free to add in your own opinions! I haven't tried to "type" all of the characters. I'll probably come back to this later and give my thoughts on others. Blueberry Muffin has me stumped.
I would say she is an ENFJ. She has INFP qualities, too. One of her defining qualities is extroversion, however, and she is a leader, so I would say the ENFJ outweighs the INFP.
Easily an INFP, with ISFP traits. Many introverts act like extroverts around their circle of friends, and introversion isn't the same as being anti-social.
Angel Cake seems like a very dramatic ENFP, with her stubborn streak bringing out INTJ and ESTJ traits in negative forms.
ESFP, although I debated between types and won't be surprised if someone else has a different opinion.
I think she's a classic ESTJ, more so as she ages. Yes, one can be an anti-social extrovert just as one can be a social introvert.
I think she's something of an INTJ and something of an ESTP, maybe an equal mixture.
She's an INTP with loyalties. Actually, she's a mixture of an INFJ, an INTP, and an ENTP. Overall, she's an INTP.
She seems like an ENFJ, too, simply a very different one from Strawberry and a more easily mislead one when she grows older.
Purple Pie Man:
Ultimately, he is an INTJ if not a typical one. Ginger Snap is a typical INTJ, focused on her projects in an original yet logical way. Purple Pie Man is eccentric and chooses to ignore patterns regardless of whether or not he sees patterns, so his personality type is harder to pinpoint. He also has a mixture of IN/P traits and ENTJ traits, the latter not being surprising since it's only one letter away from his personality type. In fact, he subconsciously wishes he were an ENTJ and he tries to come across as one.
Grapes is, like her brother, complicatedly layered and so her core personality is difficult to determine. I say she is an ENFP. She can come across as several types. She can come across as an ESFP in positive ways, and she somewhat seems like an ENTP in negative ways. Professor Grapes is a mixture of an ESTJ and an ENFJ. Gladys is an ENFP gone bad. The most overlooked part of Grapes, blink and you miss it, is a bit of INFJ parts (that this website explains better than the other one I linked if you scroll down to the second description written by Marina Margaret Heiss). All this aside, I think Sour Grapes is an ENFP who can easily be mistaken for something else. I also think she would love to be more of an ENFJ.