- 6 egg yolks
- 2 cups white sugar
- 4 lemons
- 1/2 cup butter
- Mix egg yolks with sugar, grated rinds from 2 lemons, and juice from 4 lemons and cook over boiling water, stirring constantly, until sugar dissolves. Add butter and continue cooking, stirring constantly, for 20 minutes or until filling is smooth and very thick. Cool, then spread between layers of cooled cake.