In a medium saucepan, whisk together dark brown sugar, molasses, and water. Bring to a boil, whisking occasionally until the sugar has dissolved.

Add cinnamon sticks, allspice berries, cloves, and grated ginger. Whisk to combine.

Lower heat and simmer for about 15-20 minutes, stirring occasionally. The mixture should be slightly thickened.

Strain syrup through a fine mesh strainer if using whole spices. Let cool to room temperature, then transfer to an airtight container.

In a cocktail shaker with ice, add vodka, Irish cream, coffee liqueur, gingerbread syrup, and cooled espresso coffee.

Shake vigorously for about 10 seconds.

Pour into a martini glass, garnish with a gingerbread cookie, serve, and enjoy.