In a blender puree the strawberries, 1 banana, and yogurt. Thinly slice the remaining banana and place 2 to 3 slices in each of 9 3-ounce pop molds, pressing against the side of the mold. Fill molds with strawberry mixture. Insert plastic pop sticks or cover with foil and make slits for wooden sticks. Freeze until firm, 3 to 4 hours.