Surprise bday ideas? (he's turning 20...)?

so we're sophs in college. one of my guy friends is turing 20 in april. (i dont like him...only as FRIENDS) i was planning on suprising him by baking a cake (any ideas??)...i would im his roommate(who ive had a small crush on for a lil while now..) and ask him if it was ok w/ him. is this ok?