In a medium saucepan, combine 1 cup of unsalted butter, 1 cup of brown sugar, and 1/2 cup of syrup over medium heat. Stir continuously until melted and smooth, about 5-7 minutes.

Dissolve 1 teaspoon of baking soda in 1/2 cup of hot coffee and stir until fully dissolved.

In a large mixing bowl, whisk together 4 cups of flour, 1 tablespoon of ginger, 1 tablespoon of cinnamon, 1/2 teaspoon of nutmeg, 1/2 teaspoon of salt, and 1 teaspoon of cream of tartar.

Pour the cooled butter-sugar mixture into the dry ingredients and mix until a loose dough forms.

Allow the dough to cool for 5 minutes, then incorporate 1 beaten egg.

Cover with plastic wrap and refrigerate for at least 12 hours, up to 5 days.

Preheat oven to 375°F (190°C) and prepare baking sheets with parchment paper.

On a floured surface, roll out the dough to about 1/4 inch thick, cut into desired shapes, and arrange on baking sheets.

Bake cookies for 7-9 minutes until edges are set and centers are soft.

Once cooled, fill half of the cookies with jam or chocolate spread and sandwich them.