In a saucepan, combine sugar, dark molasses, and butter (Amish or European). Add ginger juice. Simmer over medium-low heat, whisking constantly for 3-5 minutes until sugar dissolves and the mixture thickens. Let it cool.
In a medium-size bowl, whisk together flour, ground ginger, cinnamon, baking powder, baking soda, and salt. Set aside.
Whisk together the cooled molasses mixture and the lightly beaten egg in a large mixing bowl.
Gradually add the flour mixture. Mix until just combined and the dough is sticky. Add 1 tsp of ginger juice or water if the dough is dry.
Wrap the dough and refrigerate it for at least 2 hours, preferably 24 hours.
Preheat the oven to 350°F (175°C). Roll out the dough to a thickness of ¼ inch.
Cut out desired shapes and place them on a baking sheet lined with parchment paper. Refrigerate for 30 min.
Bake at 350°F for 8-10 minutes. The cookies should be puffed and no longer shiny when they are ready.
