Hi barb-I've been checking thru my books and found a recipe very similar to yours in
Bernard Clayton's "New Complete Book of Breads" which I've always found to be very reliable. According to this tome, your and Shaun's recipe should work fine.
Here's Clayton's recipe:
Makes 8 to 12
Popovers are good to eat!. Popovers are unpredicatable. kThere isn't very much to a popover. It is an ungainly-looking medium for getting butter, jams, jellies, and honey into the mouth.
The popover owes its fragile puffiness to steam levitation. It is done without yeast or chemicals of any kind. Only steam raises it high, and then drops it back down into a clumsy shape.
There should be a least one popover recipe in every home baker's repertoire. This is a good one.
1 Cup bread or all-purpose flour (sift before measuring)
1/4 tsp Salt
1 Tbl Sugar
1 Tbl Butter, melted, or salad oil
1 Cup Milk, room temperature
2 Large Eggs
Muffin pans, heavy cast-iron popover pans, or ovenproof custard cups, greased
Preheat the oven to 375 or 400 degrees.
In a mixing or mixer bowl combine the dry ingredients. Add the butter or oil, milk, and eggs. Beat by hand or at medium-high speed with the mixer flat beater, until very smooth, for 3 minutes.
Popover batter can also be made in a blender. Combine all of the ingredients and whirl at high speed for 45 seconds. Stop the blender and scrape down the sides after the first 10 seconds.
By Processor: Attach the steel blade. Measure all of the ingredients into the work bowl; pulse 8 or 10 times to blend thoroughly.
Fill the cups half full with batter.
Bake in the hot oven (400 degrees) for a dark brown shell with a moist interior, 40 minutes. Or bake at 375 degrees for a light popover with a drier interior. 50 to 55 minutes. Be sure to keep the door of the over closed during baking to prevent a collapse under a draft of cold air.
(If using a convection oven, reduce heat 50 degrees in either case.)
Remove the popovers from the oven. Turn from the pans and serve while hot. Or prick the popovers with a skewer or fork if you like a dry interior. Leave them in a turned-off oven, door slightly ajar, for 8 to 10 minutes.
ps. It could be that your gentle combining didn't develop enough gluten. Notice the recipe calls for considerable beating and could even be made with bread flour. Both indicate that some gluten development is required for structure.