Yup: coming this spring, Street Treats will be Seattle's mobile source for sweet stuff, occupying different locations on a daily basis, according to their site:
We’re looking at spots in lower Queen Anne, First Hill, South Lake Union, SODO, Beacon Hill, Belltown and Rainier Valley. Check back for exact locations in April 2010.
And what will they be serving, you ask? Well, owner Diane Skwiercz will be baking up a delectable array of cookies, brownies and bars (including an especially fascinating specimen called the "Butterscotch cloud", comprised ofchocolate, butterscotch and tiny marshmallows); but the truck will also stock pies from local legend (and beloved by CakeSpy) High 5 Pies and a rotating array of ice cream flavors from Half Pint.
The official launch is still TBA, but hopefully in the next month or two.