For some pies and tarts, especially those with tart fillings such as lemon curd, you will need a sweet crust. There are several ways to make a sweet crust. The simplest way is to make the basic dough, adding sugar to the flour and cutting down the liquid by 1 tablespoon: whisk 1 of the eggs in a small bowl and then add it a bit at a time. (The sugar keeps the flour from absorbing liquid, so you need less.) You can also make a classic pâte sucrée, which is a delicate, brittle sweet crust that is made almost like a cake. You cream together the butter and sugar, work in the eggs, and then work in the flour all at once. Last, you can make a buttery, rich sweet dough that is almost like cookie dough. For Basic Sweet Pie and Tart Dough, add ½ cup sugar with the flour in Basic Pie and Tart Dough and use only 1 tablespoon of egg.