Grate a teaspoon of fresh ginger using a fine grater, then set aside.
Pour the milk into a small saucepan and add the grated ginger, molasses, cinnamon, and nutmeg.
Warm the mixture over medium heat, stirring gently, until steam rises and the spices become fragrant, about 3-4 minutes.
Once steaming, remove the saucepan from heat and strain the milk through a fine mesh sieve into a bowl or measuring jug to remove ginger bits and spice clumps.
Brew a strong cup of coffee or espresso and pour about half a cup into your favorite mug.
Pour the strained, spiced milk into the mug over the coffee, stirring gently to combine.
Taste the latte and add sweetener if desired, stirring until dissolved.
Optional: top with whipped cream and a sprinkle of cinnamon for extra coziness.
Serve immediately while hot, savoring the warm aromas and spicy flavors.