Wash the lavender and dab dry. Bring cream, vanilla sugar, 50 g sugar and lavender to the boil in a saucepan and simmer over a low heat for about 15 minutes.
Soak gelatine in cold water. Pour the cream through a fine sieve into a bowl to collect the lavender. Squeeze the gelatine and dissolve in the hot cream.
Rinse four cups or moulds (each containing approx. 1/8 l) with cold water. Pour in the lavender cream and let it cool down. Cover and leave to cool for at least 6 hours.
Wash peaches, dab dry, halve, stone and cut into pieces. Puree in a tall mixing bowl with 1 tbsp. sugar, lemon juice and 1-2 tbsp. water.
Dip the moulds briefly in hot water and turn the panna cotta over onto the plates. Spread the peach puree around it.