I think this depends on what your therapeutic relationship is like, cultural context too, as well as your own history and habits, and you know these things best. What are your doubts, exactly? I mean, it sounds like you feel safe with your therapist and have given a gift in the past.

For me, your gift seems appropriate and thoughtful. I've given larger gifts to my therapist on his birthday. Then again, to me giving things like food / drink / a mug is symbolic, and I am personally used to exchanging larger gifts on special occasions (that is more than just one thing), so it's not just my therapist for whom I do this. It's more about what I enjoy doing for people in my life whom I cherish.

I also made something similar for my therapist a couple of years ago, also on his birthday - I gave him a little porcelain box with things I appreciate about him as a therapist and which have helped me throughout the years of working together. It was one of the gifts he seemed to be happiest about. I think that kind of gift is the most meaningful - I've also done similar stuff for other people in my life.

My therapist likes getting gifts. He gets all cheerful, like a child on Christmas morning. I like expressing my appreciation, gratitude, or love through gifts (I started it, he never even mentioned how he felt about getting gifts before I gave him something). So that's why it mostly works out in my therapy.