Baking powder is a leavener that makes baked goods light and airy and helps them rise. Unfortunately, if you use inactive baking powder—that is, baking powder that's gone bad—in a recipe, you're ...
“You can use it for a variety of items ... how much baking soda (which causes batters and doughs to spread) or baking powder (which causes it to puff) is mixed in with the flour,” she says.