On the Jewish holiday of Purim, friends and neighbors exchange gifts of ready-to-eat foods. These filled cookies come from the kitchens of Sephardic Jewry to commemorate the heroic Queen Esther. As King Ahasuerus' wife, she hid her Jewish origins until the time came to reveal herself and foil evil Haman's plot to annihilate her people. Legend says that in order to eat only kosher foods while living in the royal palace, Esther ate only raw fruit, nuts, and seeds. So Jews celebrating Purim "hide" a rich, sweet filling based on those foods in pastry.
Place the dates, butter, and milk in a double boiler and cook for 5 minutes over high heat, stirring a few times. Remove from heat and let cool. Take 1 teaspoon at a time and roll into balls.
In a medium-sized bowl, dissolve the yeast in the water. Add the flour, baking powder, salt, fennel or cinnamon, and butter. Mix until a soft dough forms and shape into a ball. Cover with a plastic bag or damp cloth. Let rise at room temperature 1 hour or until doubled in volume.
Preheat the oven to 425 degrees.
Divide the dough into 4 equal pieces and roll each out to ¼-inch thickness. Cut each into rounds using a 3-inch diameter cookie cutter. Brush the rounds with a little water.
Place 1 ball of filling at the center of each pastry round and pinch the sides upwards to make a closed bundle. Press your fingers down all around the edges to seal or use the tines of a fork.
Flip over and flatten slightly with the rolling pin. Pierce with a fork in several places. Paint the pastries with an egg white and sprinkle sesame seeds on top. Bake for 25 minutes. Remove from the oven and serve.