Hi roguzman11,
Some thoughts:
I assume that every recipe will be in a different design page. You will need a button on every page add a key/value pair on the localStorage. To show if the page is in favs you should query if the key(that can be the name of design) exists and then show something like an image for indicate that the page is a favorite and hide the button.
For create the list of added pages in favs you can use the Populate Custom List Example and make some tweaks to load the elements saved on localStorage