For the dough: Mix the flour, semolina, baking powder and salt in a large bowl. Add the margarine and mix together with your fingers until small pea-size clumps form. Mix in warm water, a little at a time (up to 1/2 cup), until a soft dough forms. Shape the dough into 36 balls.
Preheat the oven to 375 degrees F. Put the sesame seeds on a plate. Place a dough ball on a cutting board and flatten into a 1/4-inch-thick round with your palm. Top with about a teaspoon of the filling. Fold the dough over the filling. Press the edges together, gently twisting with your thumb to form a fluted edge. Dip into the sesame seeds and place on a baking sheet. Repeat with the remaining dough balls. Reserve the extra filling for another use.
Bake the sambousak until lightly golden brown, about 15 minutes.