1Preheat oven to 350 degrees F (175 degrees C). Line 15 muffin cups with paper muffin liners.
2Sift the flour, cornstarch , baking powder, cinnamon, nutmeg, and salt together in a bowl.
3Beat the butter and sugar with an electric mixer in a large bowl until light and fluffy. Add the eggs one at a time, allowing each egg to blend into the butter mixture before adding the next. Beat in the vanilla with the last egg. Mix in the flour mixture alternately with the milk. Pour the batter into the prepared muffin cups.
4Bake in the preheated oven until golden and the tops spring back when lightly pressed, 15 to 20 minutes.