I found this in my Grandmother’s recipe book, and just after this recipe is the following one. By the way, I can’t imagine beating anything for 15 minutes so I am assuming this was before electric mixers.
1 cup flour
1 teaspoon butter
1/2 teaspoon salt
1 1/2 cups milk
2 eggs
Beat 15 minutes. Bake at 350º
-Alice Senger Hutchins
Marion's Improved Popover Recipe
1 cup milk
3 eggs
1 cup flour
salt
Butter tins more than adequately. Bake in 400º oven for 10 minutes, decrease heat to 325º for 20 minutes.
-Marion Hutchins