How do i muster up the courage to ask a Very hot girl out? i need help!?

She is the only girl i would consider asking out. I just need help on how to do it. When we see each other, we talk, but i can never ask more than "any plan for the weekend" or " hows things been goin lately?" Even if she says nothing is planned, i still can't be brave and ask her. i catch her staring at me in cl, and when I look back, she doesn't look away, she just smiles and keeps on staring. No matter what she always says hi and smiles. I would like to know if u think that she likes me, and if she does, how should i ask her out? Dinner? Movie? Then if i do finally ask her, then how do i ask her, what do i say? please answer this question. I really would like to date this girl.