For the recipe you will need:
flour – 500g
butter – 100g
sugar – 100g
egg – 2 pcs.
milk – 200 ml
dry yeast – 1 tsp
salt – to taste
vegetable oil (for deep frying)
strawberry jam – 500 ml.
To make Strawberry Donuts:

Prepare dough for donuts in the sponge method: stir sugar, yeast and flour in warm milk. Leave for 20 minutes for the yeast to start working and a foam cap appears.

Add the egg, salt, softened butter and the rest of the flour to the approached dough. Knead the dough and leave for proofing in a warm place. When the dough has risen, punch it down and let it rise again.

Divide the risen dough into 12 pieces, shape them into balls, which are laid out on a floured surface and left under a towel for 20 minutes.

Fry donuts over medium heat in hot vegetable oil on both sides until golden brown.

Transfer the finished donuts to a paper towel and let the excess oil drain.

Fill warm donuts with strawberry jam using a pastry syringe and serve immediately.