UINavigationBar UIBarButtonItems much larger click area than required

This is the only solution I found. Create a container of the custom button:

//Create a container for the button
UIView *buttonContainer = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 55, 44)];

//Create a smaller button
UIButton *closeButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 55, 25)];
[closeButton setTitle:@"Cancel" forState:UIControlStateNormal];
//center the title
closeButton.titleEdgeInsets = UIEdgeInsetsMake(23, 0, 0, 0);

[buttonContainer addSubview:closeButton];
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:buttonContainer];