First, prepare the baking dish by grease with sunflower oil or melted butter.
Open the Phyllo sheets and use as per the package directions.
In a large bowl prepare a mixture of the eggs, white cheese, Bulgarian plain yogurt, and baking soda. You can use a fork to break apart the feta.
Preheat the oven to 400℉.
Small amounts of mixture filling and of sunflower oil or melted butter are layered between individual sheets. When you place half of the sheets in the baking dish a large portion of the filling mixture is spread over the sheet. The remaining sheets and filling are then layered on top in a similar way.
When you place the last sheet of the Banitsa, lightly brush the top with melted butter.
The pastry is then placed in the oven and baked for 45-50 minutes until reaches a golden brown color on top.
Let it cool slice and serve with ayran or boza.