Combine apples, preserve, cinnamon, lemon peel and nutmeg in a large saucepan and cook over low heat until apples are very soft, stirring frequently to prevent scorching.
Transfer mixture to blender or food processor and puree.
Set aside.
Place yolks, sugar and cornstarch in top of double boiler and whisk until smooth.
Add warm milk.
Place mixture over simmering water and cook until thoroughly heated and slightly thickened, about 20 minutes stirring frequently.
Add gelatine and vanilla; whisk until gelatine dissolves about 2 minutes.
Transfer mixture to large bowl and chill until it just begins to set.
Whip cream and fold into chilled mixture.
Add apple puree and whisk gently to blend.
Taste and add more nutmeg and cinnamon if you wish.
Pour into a 6 cup mould and chill.
Just before serving, unmould onto a plate.
Spoon some Apricot Sauce around the mousse.
Serve remaining sauce in sauce boat.