How to build up thickness of wrist?

I was just thinking, looking myself at mirror, since I have decent arm muscles but my wrists are ridiculously thin and my hands look almost girly. I actually measured my wrists and they have only about 12cm girth. Is it possible to make wrists thicker and hands larger?

The only way to increase your wrist size, is to put on some weight. You need to do that by eating more calories than you burn.