There's no need for artificial coloring or flavoring when recreating this chains delicious "limited-time only" holiday milkshake. Real canned pumpkin and pumpkin pie spices will do the trick in this Top Secret version. For the spices, rather than gathering up four costly bottles to use only a small amount from each, toss some pumpkin pie spice into your basket. Its a handy blend of cinnamon, ginger, nutmeg, and allspice that will be near the other spices in your market - McCormick makes a small size that's cheap. Combine everything below in a blender until smooth, and in a flash youve whipped up two servings of a delicious duplicate that can now be enjoyed any time of the year. Source: "Top Secret Recipes Unlocked" by Todd Wilbur.