1 C all purpose flour
1 C milk, warm to 110-120F
1 tsp kosher salt
3 large eggs+ 1 egg white*, room temperature
2 Tbsp melted butter
Optional: ½ C shredded gruyere or swiss cheese, 1 Tbsp thinly sliced chives or scallions, black pepper to taste
Place oven rack on the lowest position in your oven (removing the other rack if needed so you have 6” clear above the top of your pan). Place your popover pan or 2 – 12 cup muffin tins onto the rack and turn the oven on to preheat to 450F. You want the pans to be hot – so preheat for least 15 minutes. If using muffin tins you will fill every other well, staggering 6 in each tin so there’s plenty of air circulation around each popover – they need this to “pop” and rise fully.
Warm the milk and then transfer it into a 4C measuring cup and whisk in the eggs, egg white, salt and butter until evenly combined. Whisk in the flour until smooth – consistency will be pourable (no lumps!) If you are making the savory option stir in the grated cheese, chives and black pepper.
When the oven is preheated, work quickly to fill the pans: carefully remove the hot pans and spray the wells with baking spray (or quickly brush with melted butter) – remember, if using muffin tins it’s every other, staggering so you aren’t filling any adjacent wells. Pour popover batter into each buttered well filling it to about ½” from the top and get it back into the oven. Once all of the popovers are in the oven bake for 15 minutes with the oven door closed – DO NOT OPEN – but DO, turn the oven light on and watch them pop through the door. It’s cool!
After 15 minutes, turn the oven down to 375F and bake for 15 minutes longer. Open the oven door and quickly poke each with a wooden skewer or tip of a sharp knife to let the steam escape – bake for another 3-5 minutes until deeply golden browned and crisp. Remove from the open and pull them out of their well and just set them on top of the tin for a minute to cool slightly. Serve immediately – be careful tearing into them – the inside is hot! Store any leftovers in an airtight bag in the refrigerator – reheat in a toaster oven and enjoy!
* If you don’t have an extra egg white laying around, you can leave it out, but it helps the popovers rise nice and tall and makes them extra crispy.