Preheat your oven to 350°F (175°C) and prepare a 12-cup muffin tin by greasing it lightly or lining with paper liners. This step ensures the muffins release easily after baking.

In a large mixing bowl, whisk together the flour, brown sugar, baking soda, cinnamon, ginger, salt, nutmeg, and cocoa powder if using. Make sure everything is evenly blended.

In a separate medium bowl, whisk the egg, molasses, buttermilk, and melted butter until smooth. This creates the rich, spiced base for your muffins.

Pour the wet ingredients into the bowl with the dry ingredients. Stir gently with a spatula or wooden spoon until just combined—overmixing can make the muffins dense.

Divide the batter evenly among the prepared muffin cups, filling each about three-quarters full so they have room to rise while baking.

Bake for 15–20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Avoid overbaking to keep them moist and tender.

Let the muffins cool in the tin for 5 minutes, then transfer them to a wire rack to finish cooling completely before serving or storing.