VS 2013 Add Scaffold - No MVC 5 node

I am experimenting with MVC 5 / VS 2013. I have two sample projects. In one project if I right click on the (for example) "Controllers" folder and choose Add/New Scaffolded Item, I get a dialog with nodes for "MVC" and "Web API". In the other project I only see the "WEB API" option. All guidance as to what's causing this different behaviour is greatly appreciated!