3 large eggs, room temperature
1 1/2 cups whole milk, room temperature
1 1/2 cups all-purpose flour
1 1/4 teaspoons salt
vegetable-oil nonstick cooking spray
If eggs and milk are cold, before combining, submerge whole eggs in warm water for 10 minutes and heat milk until just warm. Preheat oven to 450 degree F with a nonstick popover pan on rack in lowest position.
Combine egg and milk in a large bowl and whisk vigorously until very frothy, about 1 minute. Add flour and salt and whisk until batter is the consistency of heavy cream with some small lumps and air bubbles remaining.
Remove popover pan from oven and coast with cooking spray. Fill popover cups about three-quarters (75%) full with batter. Bake 20 minutes, then reduce temperature to 350 degree F. Bake until golden brown, about 20 minutes more.
Remove the popover pan from the oven and turn them out on a wire rack immediately and poke a small opening in the side o each with a paring knife to let the steam escape. Serve immediately.