I also really think food is something that should never be punishment or reward. It can lead to some really screwed up eating habits!
If you have already said she can't have them, and she already does not respect anything you say or want, if you now give them to her - you are further reenforcing her already strong belief that she does not have to listen to anything you say or do anything you want.
There is no law against pancakes on any day of the year.
You can decide next week, or the week after that, to have pancakes for dinner (not that you tell her that of course)
If you don't ever get up, then there must be something you are doing that is meeting whatever need she has. Or she would not keep doing it.
Do you let her stay with you?
Do you give her attention?
"her dad never leaves her and 'why did I have her only to leave her with other people"
Where's she getting that from? Is your ex behaving as he should? That sounds like an odd thing for a 7 year old to say. Has that been said to her or within her hearing?
Maybe you could see if there is a course you can take that could teach you some different strategies?
Don't allow her to 'guilt' you.
You really need to honestly examine yourself here. Everything you say, everything you do, how you react to her in all of these situations. See what you may be doing, saying, how you can change what you do in order to change what she does.
That isn't a criticism of you! It's just that that is where we all have to start when we are faced with someone who will not behave in the way we need them to behave. How can we change what we are doing in order to get the result that we need.