1. In a large bowl, mix together ricotta cheese, sugar, vegetable oil and milk.

2. In a separate bowl, sift together flour and baking powder.
3. Add the flour to the ricotta mixture a small amount at a time mixing it and gradually forming dough into a smooth ball. The dough should be soft and pliable. If it's not, add water or flour (depending on dough thickness) to reach the result.

4. Cover with plastic wrap and refrigerate while preparing the filling.
5. Core the pears and chop them into 1 inch (about 2,5cm) cubes. Put them in a skillet and lightly fry over medium heat (without oil). Add vanilla extract, cognac or liqueur. If the pears are not sweet you can also add some sugar to taste. Stir-fry for about 2 minutes. Add the starch and stir-fry until it's dissolved and the mixture is thick. Let the filling cool.

6. Preheat oven to 350 degrees F (180 degrees C).
7. Divide the dough into two parts. Roll each part flat on a lightly floured surface into round.

8. To the middle of one of the rounds place the filling. Leave about 2 inch (about 5cm) space at the edges.

9. Cover this round with the second one. Press the edges down with your fingers, making sure no filling ingredients are on the edge.
10. To make our pie look like sunflower, make 2 inch (about 5cm) cuts around the circle (so that they look like petals).

11. Roll the petals inward slightly twisting. Press the edges down. Slightly beat the egg yolk with a fork and brush the top of the pie with it.

12. Bake for about 40 minutes, until crust is browned. Best served cold.