Starbucks offers Pumpkin Spice Whip as free topping option to celebrate Pumpkin Spice Latte’s 13th birthday   Seattle, 2016-Oct-08 — /EPR Retail News/ — To celebrate Pumpkin Spice Latte’s 13th birthday, Starbucks is offering Pumpkin Spice Whip as a free topping option now (October 6) through the weekend at participating stores in the U.S. and Canada. PSL, Starbucks most popular seasonal beverage…