Thaw phyllo dough according to package instructions.
Grease the bottom of an extra-large and deep baking pan, preferably 11-by-16-inches.
Preheat oven to 425 degrees.
Whisk the eggs in a large bowl, then stir in the cottage cheese, salt, baking powder and farmers’ cheese.
Stir in the soda water.
Cover the bottom of the pan with a single layer of phyllo dough, making sure some of the pieces hang over the sides.
Evenly sprinkle 1 tablespoon oil over the dough.
Take a piece of phyllo dough and wrinkle it into the dish with as many bumps as possible so it doesn’t lie flat. Depending on the size of the pan, use 2 to 3 pieces of dough for each layer.
Evenly sprinkle 1 tablespoon oil on the dough, including the sides and corners. Do not allow the oil to pool.
Sprinkle 1/2 to 3/4 cup egg-and-cheese mixture on the dough, including the sides, enough to make sure the edges and crevices are covered. Do not allow the mixture to pool.
Repeat laying down 2 to 3 pieces of wrinkled dough and sprinkling them with oil and the egg-and-cheese mixture until there is 1 layer of dough left.
Cover the top of the dish with that last remaining layer, folding in any excess on the sides.
Cover the top with a final layer of the egg-and-cheese mixture and oil. Do not dump any mixture leftovers on top.