Preheat oven to 450° F (232° C). Place muffin or popover tin inside.
In a small pan, warm milk.
In a medium mixing bowl, combine starter, milk, eggs and salt. Add flour until just incorporated--a few lumps are okay. Be careful not to overmix.
Carefully remove muffin or popover tin and brush with melted butter or use a nonstick spray. Quickly pour batter into every other muffin cup (or, if using a popover tin, fill every cup). Fill to ½ full.
Return to oven and bake for 10-12 minutes, then reduce heat to 350° F (177° C) . Bake for an additional 10 minutes or until popovers are golden brown and crusty.
Remove from oven and make a small slit on the side of each popover. They'll deflate a little bit.
Serve immediately and ENJOY!
Notes
Do not open the oven door while popovers are baking or they might collapse.
Try these creative and flavorful twists:
Cherry Lemon Popovers: add the juice and zest of one lemon plus ½ cup frozen cherries (chopping is optional). Pour the batter into the cups and add the cherries last (you have to be quick, LOL).
Gruyère Popovers: sprinkle up to ¾ cup Gruyère cheese, finely grated) on top of the batter before placing in the oven.
Cheddar Chive Popovers: add 1 tablespoon fresh chives (minced) and ½ cup white cheddar cheese (finely shredded) to the batter once in the pan.
Goat Cheese and Bacon Popovers: combine 3 strips bacon (cooked and crumbled), 1 tablespoon fresh chives (chopped), ¼ cup goat cheese separately, and spoon on top of the batter once in the pan.
Cinnamon-Sugar Popovers: mix 2 tablespoons light brown sugar and ½ teaspoon ground cinnamon into the batter. Immediately after the popovers are removed from the oven, brush the tops with melted butter (about 2 tablespoons) and sprinkle additional cinnamon-sugar on the top.