Beat all egg whites from two eggs in small bowl with electric mixer until soft peaks form.
Combine egg yolk, apple sauce, extract, 2 cups (560g) of the yoghurt, flour and half the blueberries in large bowl; fold in egg whites, in two batches.
Heat oiled small frying pan and pour ¼ cup (60ml) of the batter into pan. Cook until bubbles appear on surface. Turn hotcake and cook until browned lightly. Remove from pan and cover to keep warm. Repeat with remaining batter. Serve hotcakes topped with remaining yoghurt and blueberries.