Sift the flour with baking powder into a suitable container. Gradually pour in the liquid mixture and knead a dough.
Form walnut-sized balls from it and arrange them in a large tray with baking paper. Bake at 356°F (180 °C) with the fan on for about 15 min.
Once cooled, stick them in pairs using the jam and dip them in the chocolate ganache or melted chocolate only.