[mp_list_products category=] shortcode isn't working

I put this shortcode on my page:
[mp_list_products category="Cake Flavors"]

at

http://littlebiteofheaven.krthosting.com/cake-flavors/

I definitely have that category defined and I have products assigned to that category as you can see here:

http://littlebiteofheaven.krthosting.com/store/products/

What am I doing wrong?