Basically I know this girl from my friends and stuff, got to hang out with her only casually at a party or two. Sarged her a bit online,
told her she should bake me a cake she responded with I should bake her one, went into the "thats it we're getting a divorce" routine and she ate it up. We decided we should bake a cake together. So we did that tonight,

Basically she showed a ton of IOI's (twirling her hair, offering me beers when I finished, acting giddy) and I never went in for the move. When the cake was baking we sat on the couch and for the life of me I couldn't kiss her even though she moved in close sitting next to me (this is something I see I should work on.) Cake finished we got up and her roommates got home. For the next hour her roommates would not leave. Finally one went to sleep and the other started to fall asleep on the couch. In order to not fuck up the night I went in for the kiss, we kissed shortly and she whispered that her roommate wasn't asleep yet. and we stopped I kissed her again and then we talked about her roommate sleeping and that she thought it was really awkward with her being there.

Couldn't really move into any other rooms so I joked with her for like 15-20 minutes, said it was late, and got out of there.

The night was fun overall, pussied out (don't know how obvious it was) until a kinda awkward end.

How should I approach this girl, shes a neighbor and is having a party tomorrow.

Looks like the party passed. I'd just follow up and set another day 2. Invite her to your place if its easier to hook up.

I guess she doesn't have her own room? You could just mention you should watch a movie together and ask her when her roommates will all be gone. That way she knows you want to hookup and she might even ask her roommates to leave on a certain night so you can come over.

If not then make it happen at your place.