// Modify the Genesis content limit read more link
add_filter( 'get_the_content_more_link', 'sp_read_more_link' );
function sp_read_more_link() {
return '... <br /><a class="btn more-link" href="' . get_permalink() . '">Read More</a>';
}
Source:https://my.studiopress.com/documentation/snippets/post-excerpts/modify-the-content-read-more-link/