Stir 4/5 of the sugar and apple juice in a small saucepan; bring to the boil to melt the sugar. Beat the egg yolks, the whole eggs, the remaining sugar and vanilla until fluffy. Pour in the syrup while continuing to stir and keep beating until the mixture is cold. Stir in the apple liqueur and blend in the whipped cream. Line the baking tin with cling film and pour in the parfait mixture. Freeze for several hours.
Apple and caramel sauce:
Warm the white wine. Heat the sugar gently in a small saucepan until lightly caramelised. Deglaze with white wine, simmer over a mild heat for 3 minutes, pour in the apple and lemon juice, add the vanilla pod and melt the caramel in the mixture. Remove from the heat, add 3/5 of the butter and allow to melt in the mixture. Wash, core and quarter the apples and cut into slices. Lightly fry on both sides in the remaining butter and add to the caramel sauce.
Tip the parfait out of the tin with the help of the cling film, slice and serve immediately with the warm apple and caramel sauce.