Instructions

1. Preheat oven to 350 degrees.
2. Cream the butter and sugar well. Add the egg yolks one at a time, mixing after each addition. Then add the flour, then lemon zest, and juice. Whisk in the milk and mix well.
3. In a separate bowl, beat the egg whites until stiff. Fold gently into the lemon mixture until incorporated. Pour into an 8- or 9-inch pie plate or cake pan, or evenly among four 1-cup ramekins.
4. Bake for about 40 minutes, until very lightly browned around the edge and mostly set. You can use a toothpick to see if top cake layer is done, but remember that the bottom should be like custard. Sprinkle with powdered sugar and serve warm with sweetened whipped cream.