Put water, milk, sugar and yeast in the mixing bowl of the Thermomix. Mix for 2 1/2 minutes at 37 ° C on level 2.
Add both types of flour, salt and butter. Knead for 5 minutes on kneading level. Transfer the dough to a bowl and let rise for 10 minutes.
Cut the burger buns from the dough, grind to the desired size and place on the baking sheet lined with baking paper. After 5 minutes, flatten the buns a little and then cover with a cloth and let rise for 30 minutes.
Preheat the oven to 200 ° C (top / bottom heat). Brush the burger buns with milk and, if desired, sprinkle with sesame seeds.
Bake in the preheated oven at 200 ° C (top / bottom heat) on the middle rack for about 15 minutes.
Tip: I like to cover the finished hot buns with a cloth, then they stay nice and fluffy until they are consumed. If you have to wait a long time before consumption, it is best to store the cooled buns in a bag or closed bowl.