Grease 10 wells (each with a capacity of 60 ml) of a mini-ball cake mould. Mix flour with sugar and baking powder. Whisk 150 ml buttermilk with egg, oil and lemon peel. Gradually stir in the flour mixture, mix briefly to a smooth dough. Spread the dough in the bowls. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 15-20 minutes. Turn out of the tin onto a cake rack and let it cool down.
Wash and sort blueberries. Chop almonds. Sift icing sugar into a bowl and stir with 3-4 tablespoons buttermilk until smooth. Spread the icing on the gugelchen. Sprinkle with almonds and blueberries.