Cake at a Harry Potter Party! There are lots of tutorials for castle cakes/ princess cakes around, so you could adjust those (e. by chosing grey instead of pink fondant) to get a more "Hogwartsy" look!
Wishing a very Happy Birthday to JK Rowling and Harry Potter! Or maybe read them for the first time? Stop by the library and check them (or something else) out! Do you share a birthday with a favorite author or character?
Harry Potter Themed Boys Birthday Party Birthday Party Ideas