1. If you use frozen blueberries, let them stand at room temperature while you prepare the rest of the cake.
2. In a large bowl, mix together semolina and sour cream. Let stand for about 15-20 minutes.
3. Preheat oven to 350 degrees F (175 degrees C).
4. Add ricotta cheese, eggs, vanilla extract, sugar and salt to the bowl. Mix well.
5. Stir in blueberries.
6. Transfer the cake batter to a cake pan. Bake for about 40-50 minutes, until the cake is set in the middle.
7. Let cool and serve. Best served when cold.