Taco Bell won't let the chicken sandwich craze at fast-food restaurants pass it by. The quick-serve taco chain is launching the Chicken Sandwich Taco on September 2 for a limited time. Taco Bell app users can order starting August 30. The item, which will ask fans to answer whether it's a sandwich or taco, is made with chicken marinated in jalapeño buttermilk with a tortilla chip coating and wrapped in a warm flatbread with creamy chipotle sauce. Taco Bell is part of the Yum Brands Inc. /zigman2/quotes/209029767/composite YUM +0.13% lineup. Yum stock has gained 23.4% for the year to date outpacing the S&P 500 index /zigman2/quotes/210599714/realtime SPX +0.75% , which is up 19.7% for the period.