Nonna Lydia makes the smoothest, most velvety pastry cream I have ever tasted. In Italy, this basic cream with light notes of citrus and vanilla is used to fill countless pastries and cakes. The secret is using cornstarch instead of flour, which can give the cream a bit of a chalky taste and is more likely to create lumps. For most desserts, you can easily make the cream the night before and store it in the refrigerator. Just let it come to room temperature before using it.
