But the distinction is important, since there is a difference in taste and texture. And, for those who prefer the taste or texture of a sugar cookie, a shortbread cookie could be disappointing.
Sugar cookies have many ingredients, including eggs, vanilla, salt and a leavening agent such as baking powder or baking soda.
Sugar cookies are typically sweeter than shortbread cookies, have a lighter and crispier texture, and are often elaborately decorated with royal icing, like these gorgeous double heart cookies from The Baking Sheet.
Shortbread cookies are traditionally made from one part sugar, two parts butter and three parts flour. This 1-2-3 formula makes the recipe very easy to remember. They usually do not contain salt or vanilla.
Some bakers -- who prefer the texture of a shortbread cookie, but the taste of a sugar cookie -- add salt and/or vanilla to their shortbread dough. The use of salted butter versus unsalted butter can also alter the taste of the cookie.
At Mary's Cakes & Pastries, we coat our cookies with a sugar glaze, which adds sweetness, and dries hard. Then we decorate with royal icing. We sometimes dip the cookies in chocolate, or decorate them with a stiffer sugar glaze, especially when we want to avoid the egg-white based royal icing for those with egg allergies.
Traditional short paste is made with two thirds plain flour and one third fat, with a small amount of water to bring it all together.
Short paste is the preferred dough for pie and pastry crusts, and quiches, but (with added sugar) can also be made into cookies. There are many options -- just butter, half butter-half lard, with / without egg, with / without sugar -- all of which depend on the intended use of the "paste" and/or the personal preference of the baker.
When made into a cookie, short paste is cooked only until slightly firm, but still soft and pasty. Because of its delicate texture, it is usually un-iced, or topped with a soft buttercream.
So there you go, more than all you ever wanted to know about the difference between sugar, shortbread, and short paste cookies.