When making a shortbread crust for a pie or other dessert recipe, it is important to use a larger amount of fat than is called for in a traditional cookie crust recipe. The extra fat in a shortbread cookie crust allows the crust to become crispier and lighter than common pie crusts. Confectioners sugar is often used in shortbread crusts to act as a light sweetener, though granulated sugar can also be used. An extra egg yolk can be blended in to the butter and sugar mixture to add fat and bind all the ingredients together.
A shortbread crust is often made with a shortbread cookie recipe, and this recipe usually yields very crisp cookies that are harder in texture than a traditional cookie. Using white flour is often recommended for this type of crust to add lightness, despite its crispy and crumbly texture. Adding a little baking powder to the flour mixture will help the crust rise and become too airy, so omitting this common ingredient is necessary for a crispy crust. Other leavening agents like baking soda or whole eggs are also not recommended in this type of crust for this very reason.
It is important to use a high amount of fat in a shortbread cookie or crust recipe, as this helps the final product become crispy and slightly light in texture. Although butter is the common ingredient in a shortbread crust recipe, another hard fat like shortening or lard can be used as a substitute. It is important to beat the sugar in with the butter or shortening to make the mixture light and fluffy, as this will aid in the the crispiness and lightness of the crust. Any granulated sugar will be fine in this recipe, yet the most common sweetener is powdered sugar for its soft texture.
Adding a beaten egg yolk to the batter may make a shortbread crust crispier and a little lighter. This will not only add more fat to the recipe, which helps make a cookie crispier, but also helps bind the ingredients together to create a firmer dough. Depending on the actual recipe for the dessert, adding a few spices to the shortbread crust like cinnamon or ginger can help add extra flavor and color. Pure vanilla extract added to the batter can go a long way in balancing out the flavor of a shortbread crust.