Preheat oven to 350 degrees. Spray a 13 by 9-inch baking dish with cooking spray, set aside.
In a medium mixing bowl whisk together flour, ginger, cinnamon, nutmeg, cloves, baking soda and salt for 20 seconds, set aside.
In the bowl of an electric stand mixer fitted with the paddle attachment, blend together butter, brown sugar and molasses until combined.
Mix in egg and vanilla extract. With mixer set on low speed slowly add in flour mixture and mix until combined. Fold batter with a spatula as needed until batter appears to be evenly incorporated.
Push dough into prepared baking dish and spread and press into an even layer using your hands. (It will look a little shiny and "wet" - that is how it should be!)
Bake in preheated oven until bars have baked through, about 14 - 17 minutes (be careful not to over-bake). Transfer baking dish to a wire rack and let bars cool completely.