Mix lukewarm milk and water in a large mixing bowl.
Dissolve fresh yeast in it.
Add sugar, egg, vanilla and salt and mix.
Add flour in batches and knead into a firm dough.
Knead softened butter into the dough.
Then knead the dough for 7 - 8 minutes and let it rise covered in the mixing bowl in a warm place for 1 hour.
Knead the dough briefly and let it rise for another 1 hour.
Divide the dough into 9 equal pieces (100 g each for me) and shape each piece into a ball. Spread the dough balls on the work surface, cover them with a tea towel and let them rest for 15 minutes.
Roll each dough ball into a long rectangle about 0.3 cm thick and brush with softened butter. Roll up the rectangle from the long side and tape the seam.
For the heart shape: Fold the dough roll in half and glue the two ends together. Cut about 2/3 of the dough roll lengthwise along from the crease and fold up the two sides with the cut facing up. (See the pictures here above.)
For the butterfly shape: Tape the two ends of the dough roll together and fold so that the taped ends are centered at the bottom. Cut about 1/3 of the dough roll lengthwise from each of the two creases, and unfold the four sides with the cut facing up. (See the pictures above for this as well).
Spread the Plushki in heart or butterfly shape on a baking sheet lined with parchment paper with plenty of space between them and let them rise in a warm place for 30 minutes.
Whisk an egg, brush it on the Plushki and sprinkle them with brown cane sugar.
Bake the Plushki in a preheated oven at 180 °C top and bottom heat for about 20 minutes until golden brown.