Preheat oven to 450°F and place a muffin tin inside to heat. Grease each cup lightly with non-stick spray or oil.

In a bowl, whisk the eggs until frothy. Add milk and whisk to combine.

Gradually add flour and salt, mixing until smooth. Stir in melted butter.

Remove muffin tin from oven and pour batter into each cup about 2/3 full.

Bake at 450°F for 15 minutes, then reduce to 350°F and bake 15–20 more minutes until golden and puffed.

Remove popovers from tin and pierce with a knife to let steam escape. Serve warm.