To Make Almond Filling: Combine the remaining 1/4 cup white sugar, cornstarch and salt in a saucepan. Mix the beaten eggs and milk together and stir them into the sugar mixture. Cook over medium heat, stirring constantly until thick and bubbling. Cook for an additional 2 minutes. Remove from heat and add the almond liqueur and stir well. Cover the surface of the fill in with plastic wrap and chill completely before using.