In a large bowl, combine all the dry ingredients (flour, baking powder, ginger, nutmeg, cloves, cinnamon, and allspice) and set aside.
In a mixing bowl, add the molasses and warm water, and mix on medium speed for 1-2 minutes until the molasses is dissolved.
Add the melted butter and brown sugar to the molasses mixture, and mix until well combined.
Then, add the egg and vanilla extract, and continue mixing until incorporated.. Once incorporated, gradually add the dry ingredients to the mixer and mix until a firm dough forms.
Divide the dough into 4 equal parts, wrap them in plastic wrap, and refrigerate for 2 hours.
Preheat the oven to 170° C/340° F, on convection mode.
When the dough is ready, remove one portion from the fridge, flour the work surface, and roll out the dough to a thickness of about 4-5 mm (~1/4 inch).
Using cookie cutters, create gingerbread man shapes or other festive stars, and transfer them to a baking sheet lined with parchment paper.
Bake in the oven for 8 minutes and repeat the process for the remaining dough portions.
Once the cookies are baked, remove them from the oven and let them cool completely.