Preheat the oven to 425 degrees. Put the popover tin in the oven to heat. Sift the flour into a large bowl ad make a well in the center. Sprinkle the salt, sugar, cinnamon, and nutmeg in the bowl. In a small bowl, lightly the milk and vanilla wit a fork. Pour the liquid ingredients into the flour and stir. In a small bowl beat eggs and 2 tablespoons of melted butter together with a fork. Add to the flour mixture and combine well, but do not over beat. Strain through a fine-mesh strainer to remove any lumps.