Classic, I've been their quite a few times.

So easy, to just let ones emotions control our actions huh?

I would personally text back and start from ground zero, say that u noticed something that reminded you of her, and that you'll let her know when you get a chance because u've been bsy out w/ friends bla bla bla..

From their jst don't text/call her until she does, hopefully you being mysterous with what u noticed will urge her to contact u.

From their u could casually ask her if she wants to tag along to u downtown to starbucks.

I hope u get more replies from experienced PUA on here.

GL!
-jok3rz

i remember something that went along the lines of:
call and say "I know you've been dying to hear from me, so i finally broke down and called"
i would just text her "stop thinking about me and pay attention in class!" at 11.20am when she's been bored for 3 hours in class already dying to get out of class and take a lunch break. if she's bored, she'll text you back just to break the boredom.