Mix starch, egg yolk and 6 tablespoons orange juice until smooth. Caramelise the sugar in a pot until golden. Deglaze with half of the orange juice and simmer until the caramel has dissolved.
Add the rest of the orange juice and bring to the boil. Stir in the mixed starch, bring to the boil again and simmer for 2-3 minutes. Pour the mixture into four glasses (each containing approx. 150 ml) and let them cool down.
Then chill for 2-3 hours.
Cut the vanilla pod in half lengthwise and scrape out the pulp. Whip cream, icing sugar and vanilla pulp with the whisk of the hand mixer until semi-stiff. Arrange flummery and vanilla foam. Dust with cinnamon.
Cut the vanilla pod lengthwise into strips, halve the orange slices. Decorate flummery with vanilla pod and candied oranges.