Most Helpful Girl
How about instead of asking her on some serious date you just start off small by asking her if she's like to get coffee with you some time? That's a friendly gesture that doesn't imply anything too serious. I think once you spend more time with her it will become easier for you to ask her out again. Remember you have nothing to lose and it's better to know for sure than to sit around guessing and wondering.
Most Helpful Guy
Prepare yourself mentally yourself for both possibilities (being rejected and accepted) and just go for it. Next time you see her, say "Hey, can I talk to you alone / after class for a minute?" Tell her that you like her and that she's exactly your type, and ask her out. Something simple, like a walk on the beach, or coffee / lunch somewhere cute, or a movie if that's your thing.
You have nothing to lose and everything to gain, pretty much. If she says no, don't be awkward about it, just smile and say, "Ah well, it was worth a shot!". If you're as attractive as you think you are, she'll probably be flattered, even if she doesn't show it, and even if she's not interested in you.