Three Degrees of Smoothie Separation

A cake you can sip through a straw, and it's only three ingredients (with an optional fourth)? Yep, Amy's done it with this recipe: Frozen unsweetened strawberries, nonfat or nondairy milk, and butter extract, which is the secret ingredient that lends the cake taste to the drink. She says you can find it near the vanilla extract in the baking aisle.