They’re actually pastéis de nata, which is to say, custard tarts. The “Bélem” comes from the name of the neighborhood on the outskirts of Lisbon where they were first made. “Cream pastries” is the literal translation, but outside the Portuguese-speaking world they also go by the name of “cream tart” “egg pastry” or “egg tart.” They are the de-facto national pastry of Portugal, though in recent years they’re become hugely popular in parts of Southeast Asia.
But what exactly are they? The answer is they’re quite small, three-or-so-inch-across tarts. They have a puff pastry base and they’re filled with a cinnamon- and lemon-scented custard. What’s so tough about that? you might ask. Nothing, except a big part of the aesthetic of these pastéis is their blistered and blackened exterior which can only be created with a very high-heat bake…up to 750 degrees Fahrenheit, or so claim the owners of the Antiga Confeitaria de Belém — the bakery that owns the trademark on “Pastéis de Belém” (this is why they’re known as “pastéis de nata” more generally).
It seems that good results can he achieved at 550 degrees, in fact 750 seems way too hot even for a tiny tart, but we’ll see about that, won’t we?