Shortbread cookies are basically a more crumbly, melt-in-your-mouth version of a sugar cookie or butter cookie. They’re sweet, sometimes made with other spices, and have been around a very long time, first originating in Scotland. According to English Tea Store, the invention of shortbread is often attributed to Mary, Queen of Scots in the 16th century, although it could date all the way back to the 12th century.
Scottish shortbread evolved from medieval biscuit bread, which was usually any leftover dough dried out in a low oven. At some point, the yeast in the bread was replaced with sugar, and that bread became shortbread. Mary, Queen of Scots, supposedly loved Petticoat Tails, a round shortbread made with caraway seeds and cut in triangular wedges that resembled the shape of fabric pieces used to make petticoats. When it first came about, shortbread was considered a luxury because it was so expensive, and it was saved for special events, like Christmas and weddings.