Place blueberries on a sieve and defrost at room temperature for about 1 hour. Collect the juice. Put 125 g berries aside. Boil the rest of the blueberries with the drained juice, 40 g sugar and a piece of lemon peel in a pot.
Mix the starch and 5-6 tablespoons of water until smooth, stir into the blueberries and simmer for about 1 minute. Remove lemon peel, let compote cool down.
Cream fat, 75 g sugar, vanillin sugar and grated lemon peel with the whisks of the hand mixer. Stir in the eggs one by one. Mix flour and baking powder and stir in crème fraîche and milk briefly.
Fold in the blueberries that have been set aside.
Preheat the waffle iron, spread with oil and bake 6 golden brown waffles one after the other. Dust with icing sugar. Serve with blueberry compote. Whipped cream tastes good with it.