Preheat oven to 180 degrees C. Lightly grease 12 muffin cups.
In a large bowl, combine flour, baking powder, salt and nutmeg. In a separate bowl, beat together oil, 3/4 cup sugar, egg and milk. Stir egg mixture into flour mixture, just until moistened. Spoon batter into prepared muffin cups.
Bake in preheated oven for 20 to 25 minutes, until a toothpick inserted into a muffin comes out clean.
While muffins are baking, mix together 3/4 cup white sugar and 1 teaspoon cinnamon. While muffins are still hot, dip tops in melted butter and then in cinnamon sugar mixture.