Begin by pouring boiling water over the raisins in a small bowl. Let them sit for 5-10 minutes until plumped. Drain and pat dry with paper towels to remove excess moisture.

Separate the egg whites from the yolks into two different bowls, ensuring there’s no trace of yolk in the whites for proper whipping.

In a large bowl, combine the cottage cheese, salt, sugar, sour cream, semolina, and egg yolks. Add any optional ingredients like lemon zest or vanilla sugar if using. Blend everything together with a blender or food processor until the mixture is smooth; this should take about 5 minutes.

Carefully stir in the prepared raisins, ensuring they are evenly distributed within the mixture.

In a separate bowl, beat the egg whites until they are fluffy and form soft peaks.

Gently fold the whipped egg whites into the curd mixture, being careful not to deflate them. This step adds lightness to the final casserole.

Preheat your oven to 180°C (350°F) and grease your baking dish with butter. Pour the mixture into the prepared dish, smoothing the top with a spatula.

Bake in the preheated oven for 30-45 minutes or until the top is golden brown and a toothpick inserted in the center comes out clean.

Once baked, remove the casserole from the oven and allow it to cool slightly for 10 minutes. You can optionally dust it with powdered sugar before serving for an extra touch of sweetness.