I’m trying to create a custom version of the wp_list_authors function that includes custom post types

Ok, so I found the solution to this problem and I thought I’d post it here for anyone else who may stumble upon this question.

Turns out I was making this much more difficult than it needed to be. I just added a simple function to the custom site plugin I created (this could also be added to your functions.php file).

function hea_cpt_author( $query )
{
    if ( $query->is_author ) {
        $query->set( 'post_type', array( 'post', 'events', 'recipe' ) );
        remove_action( 'pre_get_posts', 'custom_post_author_archive' );
    }
}
add_action( 'pre_get_posts', 'hea_cpt_author' );

The hea_cpt_author portion can be whatever you want to name your function.