Start off with the cream to allow it to cool. For the cream, put the milk on the stove, add the sugar, dissolve the starch in a little water and add it while constantly stirring.
When the mixture thickens, take it off the heat, pour it into an oven dish and cover it with clear foil. While the cream is cooling, prepare the filling. Divide the egg yolks from the whites. Beat the egg whites with the sugar into snow. Add the egg yolks one at a time while constantly stirring.
Add the yoghurt, oil, the semolina mixed with baking powder and stop the mixer. Flavor with vanilla. Take a phyllo pastry sheet, brush it with the stuffing, put a second phyllo pastry sheet on it, smear it with the stuffing, put a third on it, coat again, add a fourth phyllo pastry sheet, but do not smear it with stuffing, put cream on it instead.
Turn the edges of the phyllo pastry sheets inward and roll it up. Repeat this procedure until you run out of phyllo pastry sheets. Put the rolled up phyllo pastry in an oven dish, covered with baking paper.
Top them with melted butter and bake at 338°F (170 °C) for 30 minutes. Sprinkle it with powdered sugar and slice it up once cooled.