After the batter has rested, spray the hot muffin tins with the non stick spray* and fill the tins 1/2 full with batter and top with 1-2 tablespoons of shredded Gruyere cheese (optional).
*I’ve tried butter (it burns) and I’ve tried olive oil and vegetable oil (they smoke). Pam non stick spray works best.
Do not open the door while they’re baking! I mean it. They’ll fall. You’ll cry. It’ll just be so sad. Enjoy with butter, jam or as bread for mini popover sandwiches. As an alternative experiment by adding 1/4 cup powdered parmesan cheese or 2 tablespoons of your favorite dried herb mix like Penzey’s Fox Point.
Gruyere cheese is a French cheese very similar to Swiss cheese. If you have difficulty finding it, substitute shredded Swiss cheese.