Preheat oven to 450 degrees. Place 1/2 a teaspoon butter in each popover cup, place in the oven to melt, and set aside.

In a medium bowl combine the eggs, milk, flour, and salt until you have a thin batter. Fill each popover cup 1/2 full with batter and bake at 450 degrees  for 20 minutes. Then decrease the oven temperature to 350 degrees and bake for an additional 20 minutes.

Remove from the oven and serve warm with a side of homemade jam or local honey.