Thaw the dough first if it is frozen. Cover it with a damp towel, otherwise it will dry out quickly. Melt the butter to brush the dough. Wash the apples, prunes and dry. Cut into medium sized cubes. Prepare a baking tray and preheat the oven at 180 degrees.
Prepare the filling. Mix chopped apples and prunes in a bowl. Add powdered sugar, cinnamon and mix.
Prepare the dough. Place a sheet of baking parchment on a baking sheet and a sheet of dough on top. Be careful with the thin phyllo dough and work quickly. Spread bio-yogurt all over the sheet. Then place the filling on one side of the sheet, leaving a little space around the edges and roll it up. Repeat with the other sheet.
Bake phyllo dough with fruit. Grease the rolls with butter and place in a preheated oven. Bake at 180 degrees for 15 minutes.
Before serving, dust the fruit filo dessert with powdered sugar.