Manner of asking out a close friend

Hey r/datingadvice,

I know this question has been posed here many times, but I would still appreciate some external insight into my situation. As a student, I am finishing up my exchange year in 2 months, and basically since the beginning I've been hanging out with a girl who I've developped a crush on over the months. I tried to suppress it a couple of times, but we've since started spending more and more time together, basically daily or every two days, and people around us encouraged me to shoot my shot, claiming to see interest from both sides. I myself am a bit more sceptical (everytime I tried to imply something in that direction, it was squarely derailed, ex. today I said sth along the lines of "I could stare into your eyes for a long time", and her response was something aking to "you are starting to seem tired" and change of topic -- but also, I have Asperger's and we are both fairly reserved and mild-mannered people, so she might just not understand my awkward hints), but honestly, it's probably necessary just to get over the damn crush.

So here I am, the question not being if, but how. I asked people around me, what would be the best way of approaching her about this, I got everything from writing a love letter, doing a speech, starting a conversation along the lines of "so, what are we" to simply casually asking in the middle of just talking. Nonetheless, the friends I talked to about this have mostly very different personalities from hers, and not a single one agreed with another.

So, I am hoping to learn something from Reddit aggregate wisdom. My question is, to what extent do I let her know about my feelings? I feel like I could prepare some sort of love confession-esque speech, but, if this is indeed one-way, I would probably risk wierding her out and alienating what I've come to value as a really solid friendship. On the other hand, I do not want to necessarily underestimate my feelings if that would be reciprocated. The girl who suggested writing a love letter insisted that a romantic gesture could go a long way in convincing, and, as I know her quite well at this point, I'd say she'd very much appreciate it IF she is interested.

My second question is, if I am to do a speech, a "profession of love" if you will, to what extent should I insist on the possibility of us just remaining friends? Again, if I don't even mention it, I feel like it would be more difficult to reset back to normal good friends position if she's not interested. But again, I do not want to overstate it and sabotage my chances.

Thanks for any and all advice you might give!