Preheat the oven to 350°F. Line a 12 cup muffin tin with paper liners.
Add the butter and molasses to a microwave safe bowl. Heat for about 60 seconds, then whisk until blended. Set aside to cool slightly.
In a large bowl, whisk together the flour, baking soda, salt, ground cinnamon, ground ginger, and ground cloves. Make a well in the centre.
Add the packed brown sugar to the molasses mixture and whisk until combined. Add the milk and eggs, then whisk until smooth.
Pour the wet ingredients into the well in the dry ingredients. Stir quickly, just until combined and slightly lumpy. Do not overmix. Once combined, work quickly so the baking soda remains active before baking.
Using an ice cream scoop, divide the batter evenly between the 12 paper lined muffin cups. Sprinkle the tops with sparkling sugar, if using.
Bake for 18 to 22 minutes, or until the tops spring back lightly when touched and a toothpick inserted in the centre comes out clean. Begin checking the muffins at 18 minutes.
Notes
Sprinkle the sparkling sugar over the muffin batter just before baking. The moisture in the batter helps the sugar adhere to the tops as the muffins bake. Coarse sparkling sugar works best because it keeps its texture and shine in the oven