How to Make It
In a medium heatproof bowl, whisk the egg yolks with the whole egg, the lemon juice, 1 teaspoon of the lemon zest and the honey. In a medium saucepan, bring 1 inch of water to a boil. Set the bowl with the lemon mixture over the boiling water, reduce the heat to moderate and cook the mixture, whisking constantly, until thickened, about 7 minutes. Remove the bowl from the heat and whisk in the butter. Pass the curd through a fine-mesh strainer into a medium bowl.
Ladle the strained curd into 4 cups or ramekins. Press a piece of plastic wrap directly on the surface of the lemon curd to prevent a skin from forming; refrigerate until chilled, at least 3 hours. Top the curd with dollops of crème fraîche and sprinkle with the remaining lemon zest.