In a large mixing bowl, cream together 1 cup of unsalted butter with 1/2 cup granulated sugar and 1/2 cup light brown sugar until light and fluffy. Add in 1 egg and 1/2 cup of dark molasses, mixing until well combined. In a separate bowl, whisk together 4 cups of all-purpose flour, 2 teaspoons ground ginger, 2 teaspoons ground cinnamon, 1/4 teaspoon ground nutmeg, 1/4 teaspoon ground cloves, 1 teaspoon baking soda, and 1/2 teaspoon fine salt. Gradually mix in the dry ingredients until a thick dough forms.

Divide the dough into two equal portions, wrap them tightly in plastic wrap, and chill in the refrigerator for at least 1 hour, or for a quicker option, place in the freezer for 15 minutes.

While the dough chills, preheat your oven to 350°F (175°C). Prepare your baking sheets by lining them with parchment paper or silicone mats.

Once the dough is chilled, roll it out to approximately 1/4 inch thickness. Use cookie cutters to cut out your preferred shapes. If the dough feels too soft, chill it again for 15 minutes before transferring the cut-out cookies to the prepared baking sheets, spacing them about 2 inches apart.

Bake the cookies in the preheated oven for 9-10 minutes, until the edges are just set and the centers appear slightly soft. Let them cool on the baking sheets for a few minutes before transferring them to wire racks to cool completely.

In a large mixing bowl, whisk together 4 cups of powdered sugar and 2 tablespoons of meringue powder. Gradually add about 5 tablespoons of water and a teaspoon of vanilla extract, mixing until stiff peaks form.

Once your royal icing has reached the right consistency, divide it into smaller bowls for coloring. Add gel food coloring to achieve your desired shades, mixing well to incorporate.

Using piping bags fitted with small tips, decorate your cooled Gingerbread Cookies with royal icing. Allow the icing to dry completely.