Fluffy pan-fried flat cakes with filling

I've found the original recipe on Pinterest, but it was in Russian. When I've made these flat cakes, our non-Russian speaking friends liked them very much, so I've translated the recipe for them. You can check the original recipe HERE

So, here it goes!
Dough:

500 ml  yogurt
1 tsp baking soda
1 egg
2 tbsp oil
500-550 g flour
50 g butter
salt to taste

more oil for greasing and frying
more butter for greasing cakes when ready

Filling:

You can use almost anything for the filling. Just few examples:

• white cheese with herbs
• minced meat fried with onion, egg
• mushrooms fried with onion
• canned fish with hard boiled egg
• stewed cabbage
• mashed potato with herbs
• chopped green onion with hard boiled egg
• dried fruit soaked and chopped
• thick jam
• nutella

Preparation:

Pour yogurt into a large bowl and add baking soda. Set aside for 2-3 minutes until it becomes foamy. Add egg and 2 tbsp oil, mix well. Sieve the flour into the bowl with liquid mixture, knead a soft dough. It can be a little sticky, but it’s ok. Dust it with flour, cover with a towel and set aside for 10 minutes.
Grease the working surface with oil and roll the dough into a cylinder. Cut to 8-9 pieces. Roll each piece into a circle 1.5 cm thick. Put a reasonable amount of filling in the center, pinch the edges, squeeze shut, turn upside down and flatten a little with your hand. Set aside for 2-3 minutes.

Heat 2 tbsp oil in a frying pan and fry the cakes, covered, on both sides until golden brown. Grease each cake with butter when hot to make it softer when it cools down. If you make savory cakes, you can also sprinkle each one with salt, and if you’re making the sweet ones you can dust them with powdered sugar.

Enjoy!