For the batter, combine the flour with the milk and stir in the eggs. Mix until thick and smooth. Leave to rest for 15 minutes.
Rinse, peel and cut the rhubarb into pieces.
Sauté half the rhubarb in butter. Pour half of the batter over it and fry until golden brown over high heat for 3-4 minutes. Flip the pancake over and fry for an additional 3 minutes.
Keep warm in the oven at 80°C (approximately 175ºF) while making the second pancake.
Mix the quark with the yogurt, milk and cinnamon sugar until smooth.
Serve the pancakes smothered in the rich cream and dusted with powdered sugar.