Baking Powder

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A leavening agent of which the most common is double-acting baking powder, called so because it reacts first with liquids and secondly, with the heat during baking. A good substitute for 1 teaspoon of baking powder is 1/4 teaspoon baking soda plus 1/2 teaspoon cream of tartar. Periodically, check the expiration date on your can as baking powder loses its leavening power over time.