Preheat the oven to 350°F (175°C).
In a bowl, mix together the feta cheese, ricotta cheese, sugar, milk, and vanilla extract until well combined.
Brush a baking dish with some of the melted butter.
Layer half of the phyllo dough sheets in the bottom of the baking dish, brushing each sheet with melted butter.
Spread the cheese mixture evenly over the phyllo dough.
Layer the remaining phyllo dough sheets on top of the cheese mixture, brushing each sheet with melted butter.
Score the top layer of phyllo dough into squares or triangles.
Bake in the preheated oven for about 45-50 minutes, or until the phyllo dough is golden brown and crispy.
Remove from the oven and let it cool slightly.
Dust with powdered sugar and cinnamon before serving.
