Warm 200 ml of milk lukewarm. Dissolve yeast and 1 teaspoon sugar in it. Knead flour and butter, add 100 g sugar, salt and 2 eggs. Add yeast milk and knead everything with the dough hooks of the hand mixer to a smooth dough.
Cover and leave to rise in a warm place for about 1 hour.
Wash apples, quarter them, cut out the core. Cut the quarters into small cubes. Knead the diced apples under the yeast dough. Form yeast dough into a roll and cut into 20 equal pieces. Form into rolls, place on a baking tray lined with baking paper.
Cover and leave to rise for a further 30 minutes.
Whisk 1 egg and 2 tablespoons of milk. Spread the bread roll with it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for about 15 minutes.