This is a famous Russian sauce that is delicious with a cold fruit pudding such as Apple Charlotte. Alternatively, double the quantities and serve it as an exquisite dessert on its own.
2 egg yolks
2 tablespoons sugar
2 teaspoons rum
½ teaspoon vanilla essence
1 egg white
In a medium-sized mixing bowl, beat the egg yolks and sugar together with a wire whisk or rotary beater until they are thick. Beat in the rum and vanilla essence.
In a small mixing bowl, beat the egg white with a wire whisk or rotary beater until it forms stiff peaks.
With a metal spoon, carefully fold the egg white into the egg yolk mixture. Turn the mixture into a chilled serving dish and serve at once.