Whisk the flour, baking powder, salt and nutmeg in a large bowl; make a well in the center. In another large bowl, whisk the eggs, granulated sugar, maple sugar, vegetable oil and maple extract until well combined. Pour the egg mixture into the well in the flour mixture and whisk until incorporated.
Preheat a pizzelle iron until a drop of water sizzles on the surface, about 10 minutes. Lightly brush the hot surface with vegetable oil. Spoon about 1 tablespoon batter into the center of the imprint (if you have a pizzelle iron with more than one imprint, fill each with 1 tablespoon batter). Close the iron and cook until there is no more steam coming out, about 45 seconds.
Open and remove the pizzelle from the iron using a small offset spatula and transfer to a rack to cool (the pizzelle will crisp as they cool). Repeat with the remaining batter, lightly brushing the iron with more vegetable oil occasionally. Lightly dust the pizzelle with confectioners' sugar before serving.