In To Kill A Mockingbird, what was Scout's reward for reproducing Calpurnia's penmanship?

Calpurnia rewarded Scout’s writing efforts with a sandwich made with butter and sugar. 

When Scout began school, she found out that her teacher did not expect her to know how to read and write.  In fact, her teacher seemed to be particularly peeved about it and told Scout that she was doing it wrong.  Scout was already writing in cursive when she was expected to learn how to print first. 

Miss Caroline caught me writing and told me to tell my father to stop teaching me. “Besides,” she said. “We don’t write in the first grade, we print. You won’t learn to write until you’re in the third grade.” (Ch. 2) 

First grade was a disappointing experience for Scout in general, but the fact that she was scolded for knowing how to read already and writing in the wrong style was too much for her.  She blamed Calpurnia, the African-American housekeeper who taught her to write, for teaching her the wrong way.  Cal taught her to write to keep her busy on rainy days. 

She would set me a writing task by scrawling the alphabet firmly across the top of a tablet, then copying out a chapter of the Bible beneath. If I reproduced her penmanship satisfactorily, she rewarded me with an open-faced sandwich of bread and butter and sugar. (Ch. 2)

Scout learned to write very well this way.  There was “no sentimentality” that way.  Calpurnia was not an affectionate sort.  She was just trying to keep Scout out of her hair.  Scout was precocious.  She learned to write on rainy days, and she learned to read in her father’s lap.