I use egg sub all the time -- here's my favorite recipe:
MINI POPOVERS
1-1/4 cup flour
1/4 teaspoon salt
3 large eggs (3/4 cup egg sub)
1-1/4 cup milk
1 T. unsalted butter, melted
2 T. unsalted butter, cut into 12 even pieces
Batter can be mixed in food processor, blender, electric mixer, or with a hand mixer. The batter can be made ahead of time and stored in the refrigerator. Batter should be used at room temperature.
Oil or spray popover pan. Preheat oven to 400ºF and set rack in middle of oven. Preheat popover pan ~ 2 min.
Blend flour, salt, eggs, milk and the 1 T. melted butter until mixture is the consistency of heavy cream, about 1 to 2 minutes.
Place 1 small piece of butter in each cup and place back in preheated oven until butter is bubbly, about 1 minute. Fill each cup half full with batter and bake 20 minutes. Reduce temperature to 300º and continue baking 20 minutes.
Makes 12 popovers
There are also some good recipes on
this thread that call for egg sub.