Put raspberry syrup and wild blueberries in a pot and heat while stirring. Stir in vanillin sugar. Mix starch with a little cold water and stir into the blueberries. Cook for 1 minute while stirring.
Let it cool down.
Peel the bananas and cut them into pieces. Dust them very thinly with flour. Whisk the egg in a deep plate and turn the banana pieces in it. Finally, turn in the coconut flakes.
Heat the oil to 160-170 degrees (preferably in a deep fryer) and fry the banana pieces in it until light brown all around. Drain on kitchen paper. Serve together with the blueberry compote.