Sweet Potato Cake ("Sweet Potato Torta")

"Beat the butter or margarine well with a spoon and add the eggs one at a time, mixing thoroughly until smooth"

"Add the sugar, mixing always, and gradually add the milk"

"Beat the egg whites stiffly and add them to the previous mixture"

"Then, add the all-purpose flour, mixing slowly, and continue to mix gently"

"Finally, add the chopped sweet potatoes and a pinch of baking powder"

"Pour into a tall greased and floured mold and bake in a moderate oven for 30 minutes or so"

"Instead of sweet potatoes, you can use pecans or cashews"