Certain pastry is a broad term that can refer to many different types of desserts. Two examples of certain pastries are tarts and flans. Tarts are a type of pastry consisting of a sweet or savory filling in a single-crust pastry shell. Flans are a type of custard-based dessert with a caramelized top layer. Both tarts and flans are popular desserts that can be found in many bakeries and restaurants.