Move oven rack to middle position and preheat to 350 degrees F. Grease a 9x13-inch jelly roll pan with non-stick cooking spray; set aside.
In a large bowl whisk together flour, baking soda, cinnamon, ginger, nutmeg, cloves, and salt; set aside.
In the bowl of a stand mixer on medium speed, or in a large bowl using handheld beaters, cream together butter, sugars, vanilla, and molasses until light and fluffy, 2-3 minutes.
Mix in egg until completely combined. Add dry ingredients and pulse mixer/handheld beaters until flour is incorporated. Increase mixing speed to medium and mix until well combined, about 1 minute.
Spread dough evenly into prepared pan. Bake 15-20 minutes, or until darker in color and toothpick inserted comes out with just a few moist crumbs. Move pan to wire rack and cool completely before frosting.
MAKE CREAM CHEESE FROSTING:
In the bowl of a stand mixer on medium speed, or in a large bowl using handheld beaters, cream together cream cheese and butter until light and fluffy, 2-3 minutes.
Add powdered sugar and vanilla, and pulse to combine, then increase mixing speed to medium-high and mix until creamy, about 1-2 minutes.
Frost cooled cookie bars with cream cheese frosting. Garnish with holiday sprinkles, slice in 24 bars, and serve.
These will keep in an airtight container in the refrigerator for up to 5 days.
This recipe makes 24 cookie bars, so make sure you have plans for sharing them!