Halve the melon and scrape out the seeds with a teaspoon. Soak the gelatine in cold water. Squeeze the gelatine and dissolve in a small pot. Remove from the heat, stir in wine and season everything with 2-3 tablespoons of sugar.
Let it cool down a little. Put half of the raspberries and some mint leaves into the melon halves, pour the wine over them. Leave to set in the fridge for about 3 hours. Take 3 tablespoons of the milk and stir the sauce powder into it until smooth.
Bring the remaining milk and sugar to the boil. Add mixed sauce powder and bring to the boil while stirring. Leave to cool. Cut melon halves into 4 slices and arrange with the vanilla sauce, remaining raspberries and mint.