These are aptly titled Perfect Popovers! They're incredible, with golden crispy exteriors and chewy soft centers. They are buttery and luscious, just as popovers should be! Small popover pans will yield the best rise during baking and are highly recommended. However, you can also use a muffin pan (adjust the bake time as needed.)
In a food processor or blender, blend the milk, eggs, and 1 TB melted butter until combined. Add flour and salt and blend until frothy and bubbly. Leave mixture in blender.
Preheat oven to 450F, with rack on lower middle position. Let popover batter rest in blender 15 minutes while the oven heats up (this improves the batter texture.)
Place small popover tin or muffin pan (12-count) in oven for 2 minutes to warm it up. Remove from oven and immediately divide 2 TB melted butter between the cups. Quickly blend the batter once more to froth it up again and distribute evenly into each cup (fill each about halfway.)
Bake popovers 10 ninutes; do not open the oven door during baking, or it will deflate. Without opening oven, reduce heat to 350F and continue baking 10 more minutes. Now crack open oven door to check on the popovers - they should look golden brown, puffed up tall, and feel dry and hollow.
Turn popovers out onto cooling rack and quickly pierce bottoms with small knife to allow steam to escape (helps keep them puffy longer.) Serve warm with additional butter, if desired.