This sounds a lot like my daughter, especially the sugar-snack-craving thing. She would get into anything sweet, we'd find candy wrappers hidden behind the couch or under her desk from things she'd gotten into.
One of the things we did at that age was to get some long-shackle padlocks for the cabinets like these. It's basically like a baby lock but it requires a key, so the kid can't just do it themselves. All the medications and sweets were kept in locked cabinets at all times. It helps a lot for those first few minutes while you're getting up.
And... unfortunately, I just had to get up. You might consider talking to your spouse (you mentioned "we") about taking shifts so one of you can sleep in if that works out for you, or if you can be spotted some time for a nap later.
We've had the locks off the cabinets since a little after my daughter turned 10 and it's been fine - she's doing great now. She wasn't ready for that step at 9, though, so this is probably something you are going to be dealing with for a while, and you should talk to your spouse about long-term solutions and how you both are going to tackle that together.
Another user mentioned melatonin, and that helped us a lot with her going to sleep, but she still got up really early in the mornings. You could talk to your doctor about it and see if they would recommend it or not, and what dosage based on your child's weight.
Lock with adjust shackle. Mount horizontally across the handles.