In a large mixing bowl, combine the soft flour, granulated sugar, and baking powder. Mix well to ensure that all dry ingredients are evenly distributed.
Create a well in the center of the dry mixture and add the medium egg, full-fat milk, and sunflower oil. Using a wooden spoon or your hands, combine the ingredients until a soft dough forms.
Transfer the dough to a lightly floured surface and knead for about 5 minutes until it becomes smooth and elastic. Wrap the dough in plastic wrap and let it rest for at least 30 minutes.
In a separate bowl, combine the crumbled Greek feta cheese, grated sweet mizithra cheese, medium egg, granulated sugar, honey, ground cinnamon, and crushed mastic. Mix until all ingredients are well incorporated.
After resting, divide the dough into smaller portions for easier handling. Roll out each portion into thin circles, about 10 cm in diameter.
Place a generous tablespoon of the cheese filling in the center of each dough circle. Be careful not to overfill, as this may cause the pastries to burst during baking.
Fold the dough over the filling to create a half-moon shape. Press the edges firmly to seal, and use a fork to crimp the edges for an extra decorative touch.
Preheat your oven to 180°C (356°F). Arrange the filled Kalitsounia on a baking sheet lined with parchment paper. Brush the tops with the diluted egg yolk for a golden finish.
Sprinkle a little ground cinnamon over the top of each pastry. Bake in the preheated oven for 25-30 minutes, or until the Kalitsounia are golden brown and puffed.
Once baked, remove the pastries from the oven and allow them to cool slightly before serving. Enjoy them warm or at room temperature—each bite will be a delightful experience!
