Potbelly Sandwich Shop is celebrating its 40th anniversary today, June 1, with the introduction of new menu items at stores nationwide. New items include: • Birthday shake: A hand-dipped shake that tastes like a birthday cake and is blended with Potbelly’s mini butter cookies and sprinkles • Birthday marshmallow crispy bar: A combination of marshmallows and rice crispies topped with birthday frosting and sprinkles • Hot pepper jars: Hot peppers, used in signature sandwiches made at Potbelly's, will be available for guests to purchase in jars. Cy-Fair area Potbelly locations can be found at 142 Vintage Park Blvd., Houston, and at 9102 W. Sam Houston Parkway N., Houston. www.potbelly.com