Filling: Combine sugar, cornstarch, and salt in saucepan. Mix together egg yolks and milk and add gradually. to dry ingredients mixing well. Cook over low heat, stirring constantly until it boils and thickens. Boil 1 minute. Remove form heat.

Place waxed paper directly on top of pudding and set aside to cool. When cold, stir in champagne and lemon juice. Spread between layers of cake.

In small mixer bowl whip cream until stiff. Beat in sugar and vanilla. If desired, substitute 3 tablespoons champagne for vanilla, folding into stiffly beaten whipped cream.