These buttery rich sesame and pistachio-topped cookies are a popular after school treat and great for tea time. Preheat oven to 375 degrees. Line 2 cookie sheets with parchment, or use foil and spray with non-stick spray. Prepare Toppings: Place sesame seeds in a large, shallow frying pan and toast over medium heat until golden brown, stirring constantly. Transfer to a shallow dish and set aside. Place the pistachios in another dish and set aside. Beat the egg whites until frothy. Set aside. Mix Dough: Place the butter in the bowl of an electric mixer and beat on medium-high speed for 1 minute until light and fluffy. Reduce speed to low and gradually stir in the powdered sugar. Increase speed to medium-high and beat for 1 minute until mixture is fluffy. Stir in the flour and mix until well blended. The dough should be pliable and not sticky. If necessary, mix in a little more flour. Shape and Bake: Shape the dough into walnut size balls. Gently flat- ten each ball in the palm of your hand to about 2 1/2 inches in diameter. While holding the cookie in your hand, brush it well with the beaten egg white. Sprinkle with pistachios, then press the coated side of the cookie into the sesame seeds. Place the cookie on the cookie sheet with the coated side up. Repeat with the rest of the cookies. Then gently dab more egg white on the top of each cookie. The extra egg white gives the Barazik a nice glazed look. Bake for 12 to 15 minutes until lightly browned. Remove from the oven and transfer to a cooling rack. Store the cooled cookies in an airtight container. Barazik freeze well for up to 2 months.