Soak gelatine in cold water. Wash, halve and core the grapes. Stir yoghurt, lemon juice, honey and vanilla flavouring until smooth. Squeeze the gelatine and dissolve at low heat. Mix the gelatine with some yoghurt and stir into the rest of the yoghurt. Cool briefly. As soon as the cream starts to gel, whip the cream until stiff and fold it into the yoghurt.
Divide the grapes (except some for decoration) into four glasses. Pour the yoghurt cream over them. Spread the rest of the grapes over it. Chill for about 1 hour. Roast the flaked almonds in a dry pan until golden brown. Decorate the cream with flaked almonds before serving