Just Add Magic (Season 4, Episode 10)

Kelly, Hannah, Darbie, Zoe, Ish and Leo try to cook the starter in water with magical ingredients to destroy it, but they cannot. The Kelly, Zoe and Darbie go the past when Ian tied to destroy it, but nothing different, they think of cooking with it. Meanwhile, the Wessons steal the starter and cook the sourdough recipe. It results in current down, subway stops working, electronic things stop working and buildings collapse. Leo and Darbie make a plan. The protectors stop time, teleport everyone out of buildings and subways and fix the metals in buildings using magic