Preheat the oven to 350ºF. Rub your 9x13 pan with a light coat of butter to make the paper stick, and then line with parchment paper. Press it down to stick. Lightly butter the paper, too.
Sift together the flour, salt, baking soda, ginger, and cinnamon and set aside.
Cream together the butter, sugar, brown sugar, and molasses until the sugar dissolves.
Beat in the eggs one at a time until fully incorporated. Then mix in the vanilla.
Add in the flour mixture until no clumps of dry ingredients shows. Do not overmix.
Spread the batter into your prepared 9x13 pan. Sprinkle crystallized ginger on top. Bake for 20 to 25 minutes.
Allow it to cool for 5 minutes in the pan, and then use the parchment to pick it up out of the pan. Transfer the cake to a wire cooling rack to cool completely.
Cut into 24 even bars. Serve with a dusting of powdered sugar!