Preheat oven to 425°. Generously brush every other cup in two 12-count muffin pans with melted butter (it will pool a bit in the bottom of the cups).
In a blender, whirl eggs, milk, flour, 4 tbsp. parmesan, pan drippings, salt, and pepper. Pour mixture into prepared muffin pans (each cup should be about half full). Sprinkle with remaining 2 tbsp. parmesan. Bake until puffed and golden, about 20 minutes (don't worry if some popovers don't puff quite as high as others); reduce heat to 350° and bake until popovers are firm, 10 to 15 minutes.
Note: Nutritional analysis is per popover.