How to change author of recipe post type?

In the same way you do for normal posts.

You should have a ‘author’ meta box as last box on the recipe edit page. If not, you will need to enable it by checking the ‘Author’ box on the ‘Screen Options’ tab on top of the page.

Are you able to change the author for a normal post?
If not, please seek support for the wordpress core. RecipPress reloaded uses the core functionalitiy for authors. (Recipes are custom post types).

I can’t reproduce yoor problem on wordpress 4.6.1 and recipepress-reloaded 0.7.12