pre heat oven to 450. place a large baking sheet in the oven to preheat. in a shallow dish, whisk together mustard and buttermilk. place breadcrumbs in a seperate dish. dip chicken in mustard mixture then into bread crumb mixture. remove the hot baking sheet from oven and coat with cooking spray. place chicken on baking sheet and bake 6 minutes, flip and bake until golden and all the way cooked, about another 6 minutes. serve the chicken tenders with barbeque sauce.