• Preheat the oven to 350°F (175°C). Spray a 9-inch baking dish with cooking spray and set it aside.
• In a medium mixing bowl, whisk together the flour, ginger, cinnamon, nutmeg, cloves, baking soda, and salt for about 20 seconds, then set aside.
• In the bowl of an electric stand mixer fitted with the paddle attachment, blend the butter, brown sugar, and molasses until well combined.
• Add the egg and vanilla extract, then gradually mix in the flour mixture at low speed until just combined. If necessary, use a spatula to fold the batter until it is evenly incorporated.
• Pour the dough into the prepared baking dish, using your hands to spread and press it into an even layer.
• Bake in the preheated oven for about 15 minutes, or until the bars are fully baked (be careful not to over-bake).
• Remove the baking dish from the oven and allow the bars to cool completely on a wire rack.

For the cream cheese frosting:

• In the bowl of an electric stand mixer, combine the butter and cream cheese using the paddle attachment until the mixture is smooth.
• Add the sugar and vanilla powder, and mix until light and fluffy. Spread the frosting over the cooled bars.
• Slice into squares and cover. Store in the refrigerator with a lid or plastic wrap.