Sift flour, baking powder and salt into a large bowl; set aside. Beat butter and sugar in large bowl with electric mixer on high speed until light and fluffy. Add egg, milk and sesame oil; mix well. Gradually beat in flour mixture on low speed until dough begins to pull away from sides of bowl. Stir in 1/2 cup (125 ml) of the toasted sesame seeds and black sesame seeds. Divide dough in half. Form each half into a log, about 2 inches (5 cm) in diameter. Wrap in plastic wrap. Refrigerate 2 hours.