We had this with our daughter, think set off after being ill and getting used to regular night wakes and think this set off separation anxiety.
We tried giving her a bit of time to self settle and find a dummy if had lost one but this seemed to backfire and she would get wound up and then up for 2 hours minimum.
Her personality is just not suited to controlled crying or CIO so we did what we call rapid return so every cry you go comfort them (in the cot but if late going in and hysterical then cuddles first).
Once soothed (we shhhhh and stroke them) then say it's sleepy time, love you, and go to leave. If start crying then straight back and repeat. If standing then lay them down. At start might get half way out to door, then to door then outside door.
Initially might take 1-2 hours of this for 2-3 nights and then should click.
Repeat this strategy for any further deteriorations in sleep (once ruled out other causes like illness, teething, etc).
I think she needed to know we would always come and comfort her straight away.
She's a bit sensitive tbh, we did gradual retreat to improve her sleep habits slowly between 6-8 months to be super gentle.
Also agree about snack, we give 30-45 mins before start bath/bedtime routine.
Munchkin Simple Clean Straw bottle hasn't leaked for us so far.
And do you have a comforter? Think that's essential for separation anxiety. Part of the soothing is to make sure it's not at the other end of cot.
Lastly do you need to cap/extend her lunch nap or bring forward if still having? Or tweak bedtime. Need to work out if potentially undertired or overtired. My daughter has split nights if overtired just to be a contradiction! Less than an hour nap and it's guaranteed basically.
Sorry for the essay! Hope this helps.