When the plugin is deactivated, the markup shows correctly in GSDTT, I can see the image, time and calories in the snippet.
When I activate the wp-postRating, all this disappear, and in behalf I can see the star rating with related additional info.
I can’t get them to work altogether.
It looks like activation breaks my markup. I use the [ratings] shortcode beneath the post content, below the first picture of the recipe (it is actually nested then into itemtype=”http://schema.org/Recipe”)
If your theme comes with the Recipe, I don’t think it will work fine with WP-PostRatings.
If you ask me, I say disable the Google Structured Data markup in WP-PostRatings (by going to WP-Admin -> Ratings -> Rating Options) and manually populate it in your theme alongside with your Recipe Structured Data.