The 1911 copy of Royal Baker and Pastry Cook included a recipe for chocolate cakes baked in patty pans. Of course, since the recipe book is published by a baking powder company, baking powder is the most important ingredient.
My copy included a small flyer, Facts Worth Knowing, describing the differences in the different baking powders on the market then: mineral acid or alum, bone acid or phosphate, or cream of tartar from grapes. Baking powder from grapes was the most expensive, and the authors stipulate the cost shouldn’t be a factor in choosing a baking powder:
“…remember this rule: Baking powders selling from 10 to 25 cents a pound are made of Mineral-Acids; those selling from 20 to 30 cents of Bone-Acid; and those from 40 to 50 cents of Cream of Tartar derived from grapes…The use of alum in whiskey is absolutely prohibited; why not equally protect the food of our women and children?”
Here is the recipe for the little chocolate cakes.
2 tablespoons butter, 1 cup sugar, 1/2 cup water, 1 1/2 cups flour, pinch salt, 1 teaspoon Royal Baking Powder, 2 eggs, 4 tablespoons grated chocolate melted over hot water, 1 teaspoon extract vanilla. Put together as for cake with butter; bake in patty-pans in moderate oven.