Cream butter and brown sugar in the bowl of an electric mixer. Add molasses and vanilla and mix until completely combined.
Whisk flour, baking soda, spices, and salt in a medium bowl. Add dry ingredients to the butter mixture about ½ cup at a time, adding water in between. Mix until combined.
Wrap dough in plastic wrap and chill in the refrigerator for one hour, or overnight.
Preheat oven to 350°F. Line two baking sheets with parchment paper. Set aside.
Roll dough out on a floured board to ⅛ to ¼ inch thick. Use cutters to cut out shapes.
Bake for 8 to 10 minutes. Let cool on baking sheets for 5 minutes, then let cool completely on wire rack.
Decorate with royal icing and candies.
Royal Icing
In a stand mixer, add meringue powder and powdered sugar, then add vanilla and turn the mixer on low.
Pour in a half cup of water. Turn the mixer on high until it starts to increase in volume, then add a tablespoon of water at a time until the frosting falls from the whisk in a slow stream.