Mix the oat bran and baking powder in a bowl the size of the burger patty. Then add the low-fat quark, egg and salt and stir everything together. Let it steep for 10 - 12 minutes.
Cover the bowl with a plate and place in the microwave for 3 - 4 minutes at 600 - 800 watts. Then tip over and place in the microwave again for 1 minute on the plate (without cover). Then let it cool down.
After cooling, divide the roll in half and toast it for 1 - 2 minutes.