Spray 9 wells of a 12-well muffin pan with nonstick spray. Set aside.
In a medium bowl, combine flour, sugar, baking powder, salt, and 1 teaspoon nutmeg, whisking well. Set aside.
In a small bowl, combine milk, egg, and ¼ cup melted butter, stirring well. Add flour mixture, stirring just until dry ingredients are incorporated. (Don’t overtax, as this will make muffins tough. Batter will have lumps.)
Using a levered ¼-cup scoop, divide batter among prepared muffin wells.
Bake until a wooden pick inserted in centers comes out dry, approximately 15 minutes. Remove muffins to a wire rack. (At this point, muffins may be stored in an airtight container until ready to serve.)
In a small bowl, combine castor sugar and remaining 1 teaspoon nutmeg, whisking well.
When muffins are cool enough to handle, dip tops of muffins into remaining ½ cup melted butter, and then into nutmeg castor sugar.
Serve immediately.
Notes
*Ground nutmeg may be substituted, but adjust measurement to 1 teaspoon.
Recipe by TeaTime Magazine at https://teatimemagazine.com/sugar-and-spice-muffins-recipe/