Place the eggs in a medium bowl and cover with hot water (as hot as your tap will go). Let them sit for 10 minutes.
Preheat the oven to 450°F and move the oven rack to a low position (to prepare for huge popovers!). Grease the popover pan thoroughly inside each cup as well as around the top edges.
With your whisk, beat together the eggs, milk, and salt until they are combined. The yolks should be completely blended in.
Add the flour and whisk until the mixture is frothy and all large lumps are gone. Then quickly stir in the melted butter.
Divide the batter between the prepared popover cups. They should be about 3/4 of the way full.
Bake the popovers for 20 minutes without opening the oven door and then reduce the heat to 350°F(again without opening the door),. Bake for another 10 or 15 minutes. The popovers will be very golden brown.
If you plan on serving the popovers immediately, remove them from the oven, and stick the tip of a knife into the top of each, to release steam and help prevent sogginess. Slip them out of the pan, and serve.
If you want the popovers to hold their shape longer without deflating and settling quite as much, bake them for an additional 5 minutes (for a total of 40 minutes) IF you can do so without them becoming too dark. This will make them a bit sturdier, and able to hold their "popped" shape a bit longer.