Cut the pineapple lengthwise in half. Cut out the flesh and dice finely. Cut pomegranate in half, knock out seeds. Peel the remaining fruit and also cut into small cubes.
Mix all fruits with lemon juice, sugar and vanilla sugar. Place in the freezer for about 30 minutes. Form balls with an ice-cream scoop and place them in the pineapple halves. Serve decorated with whipped cream and pistachios.