• Preheat the oven to 425 degrees F. Lightly butter a 6-cup popover pan or 12-cup standard muffin pan. Place the pan in the oven while it preheats.
  1 tablespoon unsalted butter
• Whisk the milk, eggs, and melted butter together in a medium bowl until well combined.
  1 cup whole milk, 4 large eggs, 1 tablespoon unsalted butter
• Add the flour, salt, and black pepper and whisk until the batter is completely smooth. Stir in the Parmesan until evenly incorporated.
  1 cup all-purpose flour, 1/2 teaspoon fine sea salt, 1/2 teaspoon ground black pepper, 1/2 cup finely grated Parmesan cheese
• Carefully remove the hot pan from the oven. Divide the batter evenly among the popover cups, filling each about two-thirds full. If using a muffin pan, divide the batter evenly among all 12 cups.

For a popover pan

• For a popover pan, bake for 20 minutes at 425°F. Reduce the oven temperature to 350°F and continue baking for 15-20 minutes, until the popovers are deeply golden brown and crisp.

For a muffin pan

• For a muffin pan, bake for 15 minutes at 425°F. Reduce the oven temperature to 350°F and continue baking for 10-15 minutes, until puffed, deeply golden brown, and crisp.
• Remove the popovers from the pan and serve immediately.