I think by just saying it, honesty is the best policy. Unless you want to do it in a cute and creative way. But you never know if she feels the same way if you don’t ask
Just be open, honest, and speak about your feelings. Reassure her that you have no expectations and still want to be her friend, that you simply want her to know your feelings.
just be honest with how you feel. you could even sit her down and just tell her that you need to tell her something and just speak from your heart. just know that if she doesn’t feel the same way, it can affect your friendship. if you are willing to take that risk, then just do it. you just have to prepare yourself for everything.