Add the softened butter to the bowl of a stand mixer, along with the brown sugar. Beat for a few minutes until nice and fluffy.
Add the molasses, egg and vanilla and beat again until well incorporated. It will look separated, but it's fine.
In a large mixing bowl add the flour, baking soda, salt, ginger, cinnamon, allspice and cloves. Mix with a whisk.
With the stand mixer on low add the flour mixture to the molasses mixture a ½ cup at a time until it's all mixed and well incorporated.
Separate the mixture into three sections. Lay out plastic wrap and spoon the cookie dough out, then wrap with the plastic wrap and form a thin disc. Do this to all three sections of the dough.
Place in the refrigerator and allow to cool for about 4 hours.
Preheat the oven to 350°F.
Take one of the discs out of the refrigerator and empty out onto a well floured surface. With a floured rolling pin roll out the dough to about ¼" thick.
Using a snowflake cookie cutter cut out shapes and lay on a parchment paper lined cookie sheet, 1" apart.
Bake in the oven for 10 minutes.
Remove and allow to cool a minute or so then using a spatula move to a wire rack to cool completely.
Repeat with the remaining cookie dough.
Once all the gingerbread cookies are baked and cooled completely make the royal icing.
Empty the powdered sugar into a large mixing bowl, with the other ingredients and mix on medium speed until the perfect royal icing consistency has been met. This is when you allow the icing to drizzle into the bowl on top of the other icing and it holds its shape for 5 seconds before melting into the icing.
Decorate the cookies.
Notes
If you find the royal icing to be too runny add more powdered sugar. If it is too stiff add more water.