Preheat the oven to 400°F. Line a baking sheet with parchment paper.

Prepare the topping by soaking the sesame seeds in water and set aside.

Make the pastry:

In the bowl of a stand mixer add  flour, baking powder, and salt. Mix well.

Mix together the olive oil and orange juice in a large mixing cup. With mixer running, add the liquid ingredients to the dry ingredients and knead with the dough hook until the dough comes together.

Cover with plastic wrap, and set aside.

Make the filling:

In a large skillet, heat 4 tablespoons of olive oil. Add the scallions and sauté until they soften, about 4 minutes. Add in the olives and oregano, and sauté for 1 more minute.

Remove from the heat, and add the mint. Season the mixture with pepper flakes.

Roll and fill the pastry:

Divide the dough into 4 equal pieces. Lightly flour your surface or use a sheet of waxed paper. Flatten the first piece into a rectangle that is about 5 inches wide by 10 inches long.

Fill with your preferred filling. Using the waxed paper, slowly slide the paper off the dough as you roll the pastry dough over the filling as you would a jelly roll. Make sure to pinch the sides in and under, and lightly pinch the seam to ensure that the filling is enclosed.

Using both hands you can shape the roll by pressing in on the ends or slowly pulling the ends out. You should have a tight log.

To make the topping, drain the water from sesame seeds on a colander, and spread them on a tray. Lightly roll the log on the tray to cover with the sesame seeds. Place the log on the prepared cookie sheet. Repeat with the other dough and fillings, to make 4 logs.
Bake for 30-35 minutes or until the logs are a light golden brown. Move the logs to a cooling rack and let cool completely before slicing with a serrated knife.