Break up the
cake into chunks and arrange in an ovenproof dish. Slice the bananas and
toss in the lemon juice. Whip the cream and when firm, gently whip in
the juice. (If using fromage frais, just gently stir in the juice). Fold
in the bananas and spoon the mixture over the ginger cake. Top with the
sugar and place under a hot grill for 2-3 minutes to caramelize. Chill
to set firm again if you wish, or serve when required.