It’s a Piece of Cake!
Or, in other words, it’s very easy! There are quite a few expressions in English which are based on English food.
If you’re in the soup, you’re in trouble. But you’re not very intelligent if you’re half-baked. Bread is a slang expression for money, and wanting jam on it means you want some luxuries as well as the basic things in life. If you know which side your bread is buttered on, you know when you are well off. An old salt is a sailor, but if you take something with a pinch of salt you doubt whether it is true. If you are as keen as mustard, you’re very enthusiastic about something, but if it’s not your cup of tea, you don’t like it very much. When you sugar the pill, you disguise the unpleasant part of something and if a thing is sugary, it is too sentimental. A person who is worth his salt is a good worker, but someone who is saucy is rather impudent. If you cook your goose, you ruin your chances, and if you cook the books, you falsify the accounts. Finally, a storm in a teacup is a lot of fuss about nothing.
Movie related foods (Milk Duds, Buttered Popcorn, Junior Mints, Red Hots, Tootsie Rolls, etc.) do not have additional calories because they are part of the entertainment package and not part of one's personal fuel.