Preheat oven to 350°F (175°C). Grease an 8.5x4.5-inch metal loaf pan and line with parchment paper, leaving an overhang on the sides for easy removal.

In a medium bowl, whisk together all-purpose flour, ground ginger, cinnamon, nutmeg, cloves, baking soda, and salt. Set aside.

In a large mixing bowl with an electric hand mixer or stand mixer, beat the softened butter and dark brown sugar together for 2 minutes until creamy and fluffy.

Beat in the egg until smooth. Add the dark molasses and beat on medium-low until fully incorporated.

With the mixer on low speed, add the dry ingredients in two batches, alternating with the boiling water. Mix just until a smooth, pourable batter forms without overmixing.

Pour the batter into the prepared loaf pan and smooth the top with a spatula.

Bake for 50 to 55 minutes, or until a wooden skewer inserted into the center comes out clean or with a few moist crumbs. If the top browns too quickly after 35 minutes, tent loosely with aluminum foil.

Cool in the pan for 15 minutes, then use parchment handles to transfer loaf to a wire rack to cool completely.

Make frosting: Beat cream cheese and butter until smooth. Slowly add powdered sugar and vanilla extract, beating until thick, creamy, and spreadable.

Spread generous swirls of cream cheese frosting over the cooled loaf. Slice and serve!