Combine the flour, salt and baking powder in a large bowl. Cut the butter into small pieces and add to the bowl. Mix the ingredients with your hands. Add 2 eggs, the oil, yogurt, and dill and knead well until the dough is smooth.
Shape the dough into a ball, cover with plastic wrap and let rest in the fridge for 30 minutes.
Take out the dough, remove the plastic wrap, and cut the dough into two equal halves. Shape each half into a 6 inch long roll. Cut each roll into 5 pieces and transfer to a baking sheet lined with parchment paper.
Preheat oven to 375 F.
In a small bowl crumble the feta and add chopped feta and dill. Mix until fully combined with a spoon.
Flatten the dough pieces with your hands into oval shapes 1/2 inch thick. Put some feta and fresh mint on one half of each oval, leaving a 1/2 inch border. Fold the other half of the oval over the filling, press the edges together tightly, and fold the edges over a bit so the cheese doesn't spill out.
Whisk the last egg with the milk in a small bowl and brush on top of each roll. Sprinkle the sesame seeds and cumin seeds and place on the middle rack of the oven. Bake for 45 minutes.