Really unsure how to handle this strange situation

So I've been friends with a girl for 2 years now and never felt anything but lately she came on a trip with me to help with a project I was doing. Since then I've started to really like her for some reason. My first worry is if it's even worth trying anything since it could ruin the friendship. We don't hang out as much anymore but she buys me gifts now and then and she took me for lunch for my birthday. When I said I'll take her out for a Christmas dinner as a thank you she said she'd love to and then talked about how she's excited to give me my Christmas gift. I also noticed its been a long time since she did anything to friendzone me like call me her best friend or anything (I think she stopped doing this when she broke up with her boyfriend too). She sometimes acts like she likes me (sometimes she pretends to be into something she's obviously not just because I am) but lately after a bad experience she had she's done nothing but go out and drink and she barely response to me or any of our friends when we try to contact her. That doesn't mean i don't hang out with her anymore she just doesn't put in the effort to talk to me online, but she doesn't with anyone else either so its not like its just to me. She's shows some of the basic signals like smiling a lot, dressing up nice around me, laughing at all my bad jokes and today we did have a great text conversation but she took ages to reply. She definitely goes out of her way to continue being friends with me and do things with me but does she just really like me as a friend or is there something there? How should I approach this situation?

Lifes about going after what you want.

I think, as a man, you need to make your intent clear.
Ask her out on an actual date, you don't have to spit up all your feelings by going over the top, just be romantic, speak your truth.

Right now she might permanently think of you as just a friend though. Despite what you said, women just do those things around men and social places.
I agree there's more context here, but they do those things around male friends too . Women just want to look nice when going out in public.

But who knows, she might. I've had women come around as well after they broke up with their boyfriends.

She also knows your single, so your choices are either, be a man and do something about it. Or hesitate, and be autorejected as she eventually dates another man.

Say to her; "I reckon your awesome Julie, let me take you out on a proper date next week. You never know, you might fall in-love with me".

Dont use those exact words, especially if her name isn't Julie, but just be straight with her. Telling a girl you like her is not as big a deal as it seems when you're a teen. If you say you like her it doesn't mean it will suddenly ruin your friendship. If you cant handle her saying no, that could ruin your friendship. But not the liking her bit. If she says no, just accept that she isn't interested and move past it. Say "Ah well, never mind. Do you like the new Justin Beber song?". (I dont know what music you kids listen to nowadays lol, I'm not old or anything, drum n bass is my thing!). If you can simply carry on asthough nothing has happened then it will be like nothing has happened... However... She could say yes, and she could end up falling for you which would blatantly be awesome! Just be brave young Luke. Take what comes in your stride. Dont be afraid of the future. Live in the moment, the place where fear doesn't exist.

If you're honest, you can never say the wrong thing.