Preheat oven to 350 degrees F.
Whisk together flour, baking soda, spices, and salt in a large bowl. Set aside.
Beat shortening in the bowl of a standing mixer (or large bowl with a hand mixer) until fluffy.
Add both sugars and egg. Beat until well mixed, scraping sides of bowl.
Add half of the flour mixture, the hot water, and then the remaining flour mixture, mixing well between additions.
Put batter in prepared 9 x 9 inch baking pan. (I prepare my baking pans with Baker's Joy.)
Bake 30 minutes or until knife inserted in center of cake comes out clean.
Cool 10 minutes. Dust generously with powdered sugar.