Add the water, brown sugar, molasses, ginger, cinnamon, cloves, nutmeg, allspice, lightly crushed cardamom pods (if using), and vanilla to a medium saucepan and give it a quick stir.
1 cup water, 1 cup light brown sugar, packed, 3 Tablespoons molasses, 1 inch piece of ginger root (or 2 teaspoons ground ginger), 1 teaspoon cinnamon, ¼ teaspoon ground cloves, ⅛ teaspoon nutmeg, ¼ teaspoon allspice, 1 teaspoon vanilla extract, 5 lightly crushed cardamom pods (optional)