In your mixer, beat together butter, oil and sugars until smooth. Add eggs and beat until fluffy. Add powder, soda, nutmeg, cinnamon, salt vanilla, milk and flour. Beat well.
Spoon batter into liners and fill to tops. Bake for 15-17 minutes or until tops are golden and springy to the touch. Let cool 10 minutes before adding Glaze.
To make the glaze, mix melted butter, powdered sugar, vanilla and water together. Mix until smooth.
When muffins have cooled slightly, dip the muffin top into the glaze and allow the glaze to harden. Once hardened, dip a second time and allow to harden.