Prepare the Baking Pan: Preheat your oven to 180°C (350°F).

Grease a 22x22 cm (9x9 inches) baking pan with a bit of vegetable oil or line it with parchment paper to prevent the cake from sticking.

Mix the Cake Batter: In a large mixing bowl, crack 3 eggs. Add 150 grams of sugar and a pinch of salt.

Using a whisk or an electric mixer, beat the eggs and sugar together until the mixture becomes pale and fluffy.

Gradually add 100 ml of vegetable oil and 70 ml of milk, continuing to mix until well combined.

Sift 200 grams of all-purpose flour and 1 tablespoon of baking powder into the wet mixture. Fold the dry ingredients into the wet ingredients using a spatula until just combined. Be careful not to overmix to keep the batter light and airy.

Prepare the Filling: In a separate bowl, combine 250 grams of cottage cheese, 3 tablespoons of sugar, 1 tablespoon of cornstarch, and 1 egg. Mix until smooth and creamy. The cornstarch will help to thicken the filling and keep it from becoming too runny during baking.

Assemble the Cake: Pour half of the cake batter into the prepared baking pan, spreading it evenly with a spatula.

Spoon the cottage cheese filling over the batter, spreading it evenly but leaving a small border around the edges to prevent the filling from leaking out.

Pour the remaining cake batter over the filling, carefully spreading it to cover the filling completely.

Bake the Cake: Place the assembled cake in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

The top of the cake should be golden brown and the edges should start to pull away from the sides of the pan.

Cool and Serve: Once baked, remove the cake from the oven and let it cool in the pan for about 10 minutes.

Transfer the cake to a wire rack to cool completely.

Once cooled, dust the top of the cake with powdered sugar for an elegant finish.