Рогалики с Заварным Кремом ✧ Custard-Filled Buns (English Subtitles)

For the dough:
450-500 g of all-purpose flour
250 ml of warm milk
80 g of sugar
1 middle-sized egg
40 g of butter
30 g of vegetable oil
6 g of active dry yeast
1/2 tsp of salt

For the cream:
500 g of milk or any cream
1 middle-sized egg
150 g of sugar
80 g of flour or starch
8 g of vanilla sugar

egg wash to brush the tops
powdered sugar to sprinkle over the tops