Conveniently place the necessary products on your desktop. Thaw the phyllo dough as needed. Wash the apples, cut into small cubes. Prepare silicone muffin tins. Finely chop the nuts. Preheat the oven to 200 degrees.
Make the filling. Place the apples in the pan, add 1 tbsp. butter and place over medium heat. Fry the apples a little, add sugar. Stir and remove from heat.
Prepare the dough. Spread the phyllo dough on a work surface and brush it with butter. Then cover with another sheet and brush with oil again. Cut the sheet into 4 squares. Do the same with all sheets. There should be 16 squares in total.
Form into tartlets. Take a silicone muffin pan. Grease with butter and place the dough in the mold. For one tartlet you need to stack 3 squares on top of each other, slightly shifting their edges. Place apples inside each tartlet and sprinkle with nuts. Bake the phyllo tartlets for 20-30 minutes. Carefully remove the finished tartlets from the mold, transfer to a metal wire rack and cool.
Sprinkle filo tartlets with powdered sugar before serving.