You can replace the baking powder in various ways, according to the recipe, with cream of tartar, baking soda or ammonium carbonate (baker’s ammonia) for desserts.
Fresh and dried yeast for pizza, bread and focaccia can be replaced in different ways: here's how to do it and what precautions to take.
Bling baking is a key step in making sure quiches and pies don't come out with soggy bases.