Stir 4 tablespoons of juice and starch until smooth. Bring the remaining juice and vanilla sugar to the boil, stir in the mixed starch. Add blueberries and defrost while stirring. Let the compote cool down. Melt butter and let it cool down.
Whisk eggs, butter and buttermilk. Mix flour, baking powder, sugar and salt and add to the egg-fat mixture and mix to a smooth dough. Heat oil in a coated pan and bake about 16 small pancakes from the dough until golden brown. Dust with icing sugar. Add compote and maple syrup