This is a four ingredient easy Lemon Curd Recipe. Luscious, lemony, sunny, bright and bursting with fresh citrus flavor. Homemade lemon curd is made with fresh lemon juice and is extra creamy and smooth with the addition of butter.
In a medium saucepan, combine 1/2 cup plus 1 tablespoon of the sugar with the lemon juice and bring to a simmer, stirring until the sugar dissolves.
In another medium bowl, beat the egg yolks with the whole egg and the remaining 1/2 cup plus 1 tablespoon of sugar.
Pour half of the hot lemon syrup slowly into the egg mixture while whisking rapidly. Add the combined mixture back into the saucepan with the rest of the lemon-sugar mixture and cook over moderate heat, stirring constantly, until the curd just comes to a boil, about 9 minutes; it should be the consistency of sour cream. If the curd has any lumps you can strain the curd through the sieve.
Let the lemon curd cool to room temperature, then whisk in the softened butter until the curd is light and fluffy. Add the lemon zest and mix thoroughly.