Thank you Caridad,
I sent them an email and I got this answer: Thank you for your email. Unfortunately, I am not aware of any themes with WordPress built in nor do we have the bandwidth right now to share the APIs that may be required to build our technology into a theme. I'm sorry I can't be more helpful right now.
So I think it will be easier to use Easy Recipe and try to build that into the theme. i know it is done before with the Genesis Foodie theme (https://shaybocks.com/2013/09/26/foodie-a-genesis-2-0-child-theme/), so it must be possible:-)
About the print button, I found this and I think that will do the job: http://themefuse.com/blog/how-to-make-your-wordpress-site-look-great-in-print/
But if I can implement Easy Recipe, I won't need that.