Preheat the oven to 350°F. Line an 8x8 baking pan with parchment paper, letting the ends overhang, and set aside.
Whisk the flour, baking powder, baking soda, ginger, cinnamon, allspice, nutmeg, cloves, and salt together in a mixing bowl and set aside.
In a large mixing bowl, whisk the molasses, sugar, oil, vanilla, apple cider vinegar, and hot water until smooth.
Whisk the dry ingredients into the wet until just combined. It's ok if there are a few lumps, but don't leave any white flour showing. Do not over mix or the cake may come out dense and rubbery.
Pour the batter into the prepared baking pan and bake for 30 to 35 minutes or until a toothpick inserted into the center comes out clean.
Let cool in the pan on a wire cooling rack for 10 to 15 minutes. Using the ends of the parchment paper that are overhanging the sides, pull the cake out of the pan and place on the cooling rack to continue cooling.
Once cool, dust with powdered sugar and cut into squares.