In a mixing bowl, beat the cottage cheese with the egg until well combined. Add the vanilla sugar and granulated sugar, mixing thoroughly. Pour in the vegetable oil and stir to combine.

Sift the flour and baking powder together, then gradually incorporate into the wet mixture. Knead the dough by hand until it becomes soft and elastic.

Form the dough into a ball and divide it into two equal halves. Cut each half into 5 smaller pieces and shape each piece into a ball. Place the balls on a plate and cover with cling film. Refrigerate briefly.

Peel and core the apples, then cut them into small cubes. In a deep pan, melt the butter over medium heat. Add the cubed apples and sprinkle with cinnamon. Stir and cook until the apples are tender.

Sprinkle the cornstarch over the cooked apples, mix well, and remove from heat. Set the filling aside to cool slightly.

Retrieve the dough from the fridge. Flatten each ball into a disc with a diameter of 5-6 centimeters (2-2.5 inches). Place a spoonful of apple filling on one half, and then fold the other half over to create a pocket. Seal the edges.

Arrange the pastries on a baking dish lined with parchment paper. Brush the tops with a bit of fresh milk. Bake in a preheated oven at 170 degrees Celsius (340 degrees Fahrenheit) for 15-20 minutes or until golden brown.

Once baked, remove the pastries from the oven and brush each with a little melted butter. Sprinkle a mixture of granulated sugar and cinnamon on top before transferring them to a serving dish.