Use the "Artistic Text" tool.
To center the Artistic text box vertically, you must also specify its horizontal alignment (due to moronic interface design). Specify left or right alignment and you'll get pretty close. Use the left and right arrows to finish the job.
But don't do any alignment until you're sure you won't be changing the text, or its properties, because any such change will screw up the vertical centering. (Another moronic "feature.")