Preheat the oven to 425°F. Line a cupcake/muffin tin with 12 paper muffin cups.
In a mixing bowl, cream together the butter, vegetable oil, and sugars until smooth. Add the eggs one at a time.
Blend in the baking powder, baking soda, nutmeg, cinnamon, salt, and vanilla.
Stir the flour into the butter mixture alternately with the milk, beginning and ending with the flour and making sure everything is thoroughly combined. Don't overmix it though. Just enough to make sure it is all combined.
Spoon the batter evenly into the 12 prepared muffin cups.
Bake the muffins for 15 to 17 minutes, or until they’re a pale golden brown. Do the toothpick test. If it comes out clean, they are done. Cool for a few minutes while you make the glaze.
In a medium bowl, mix together the melted butter, confectioners’ sugar, vanilla and water. Whisk until smooth.
Dip the muffin tops into the glaze and allow the glaze to harden. After the glaze hardens (10 minutes), I highly recommend dipping them again for a double dip muffin top.
Serving these muffins warm is the best. They will also keep in an airtight container for a day or two. You can always heat them up for about 10 seconds in the microwave to serve them warm later.