Preheat oven to 425 degrees F and position the rack in the lower third of the oven.
Generously butter a 12-cup popover tin; set aside.
In a medium bowl, whisk together the milk and eggs. Add the flour, salt and powdered sugar and whisk briefly to incorporate the dry ingredients. There may still be small lumps throughout the batter, which is fine; do not overmix.
Fill each cup of the popover tin with 5 tablespoons of the batter. Bake until the popovers are very puffed and rise above the top of the tin by 3 inches, about 30 minutes. Immediately turn the popovers out of the pan and serve warm.
Pan Note: If you're using a dark, non-stick pan, be sure to reduce the oven temperature by 25 degrees.
Serving Suggestions: Softened butter + fruit jam or jelly / bacon jam / honey or maple syrup / fresh berries / dust with powdered sugar / Nutella
Storage: Store any leftover popovers in an airtight container at room temperature for up to 3 days.
Freezing Instructions: Freeze cooled popovers in a freezer-safe container for up to a month. Don't use a bag, as these delicate pastries are more likely to get crushed or damage that way.
Reheat Instructions: Reheat from frozen or refrigerated in a microwave or toaster oven until warmed through and crispy on the outside.