Can You Adjust Line Height of Post Titles

Yes, you can use an extra CSS code to control the line height of the post titles.

Would you please elaborate as to what code to add to remove the extra line height? Thank you

You can use:

.recent-posts-widget-with-thumbnails .rpwwt-widget ul li a span.rpwwt-post-title {
	line-height: 1.5;
}

The value 1.5 is an example. If you want to know how to set valid line-height values, I recommend the explanation at https://www.w3schools.com/cssref/pr_dim_line-height.asp