Make the dough:
To a mixing bowl, add the egg yolks and sugar. Whisk for a minute until well combined and light yellow in color.
2 large egg yolks, 1/4 cup (50g) granulated sugar
In a medium bowl, whisk together flour, baking soda, and salt. Add to the egg yolk-sugar mixture.
2 cups (250g) flour, 1 teaspoon baking soda, 1/8 teaspoon salt
Add the remaining ingredients (cheese, sour cream, vanilla, and vodka).
1 package (250g) Polish twaróg cheese, 1/2 cup (110g) sour cream, 1 teaspoon vanilla extract, 1/2 tablespoon vodka
Mix the ingredients using a stand mixer fitted with a paddle attachment (speed 2) or by hand.
The dough will be sticky, try not to add any more flour.
If using cream cheese and not Polish twaróg cheese: the dough will be more sticky - cream cheese is completely smooth and twarog cheese is a crumbly curd cheese. Add two additional tablespoons of flour to the dough and then generously sprinkle the dough with flour while rolling it out.
Warm up the oil: In a wide pot, warm 6-8 cups of frying oil until it reaches 350°F (175°C). You should have at least 2 inches (5 cm) of oil in the pot.
6-8 cups frying oil
Cut out donuts:
Place the dough on a floured counter or a silicone rolling mat (highly recommended for rolling out any type of dough). Sprinkle some flour on top of the dough.
Roll out the dough to a thickness of 5/8 of an inch (1 1/2 cm) - a little bit thicker than 1/2 of an inch.
Cut out rounds with a donut/biscuit cutter (I used a 2 3/4 inch (7cm) cutter which is the perfect size for these donuts). You can cut the inner circles with a piping tip (see step-by-step photos in the body of the post).
Combine the scraps, re-roll, and repeat with the remaining dough. Place the cut-out donuts on a floured surface.
Fry 4-6 oponki at a time (depending on how wide your pot is). Place the dough in the hot oil using a lightly floured bench scraper. Fry until golden on the bottom side then turn over and fry until golden on the other side. The donuts will get slightly darker while cooling.
Take the oponki out of the oil with a spider strainer and place on a cooling rack lined with paper towels.
Leave to cool then sprinkle generously with powdered sugar.
powdered sugar
Enjoy!