Combine sugar cornstarch and salt. Add orange juice, water, lemon juice & egg. Mix well. Cook over medium heat stirring constantly, until thickened. Add buttera and cool to lukewarm. Beat cream. Stir into mixture. Break cake into 1 inch pieces. Line bottom of 8 inch square pan 2 1/2 of cake pieces. Cover with half of pudding mixture. Layer rest of cake pieces and pudding mixture. Layer rest of cake pieces and pudding. Sprinkle with coconut. Chill at least 2 hours. Cut into squares and serve.