+1/2 teaspoons baking powder

Baking powder is a dry chemical leavening agent composed primarily of sodium bicarbonate (baking soda), one or more acid salts (typically cream of tartar or sodium aluminum sulfate), and a moisture-absorbing agent such as cornstarch or flour. Modern baking powder is most commonly "double-acting," meaning it releases carbon dioxide gas in two stages: once when mixed with wet ingredients at room temperature, and again when exposed to heat during baking. Single-acting baking powder, less common today, produces all its leavening action during mixing. The ingredient is odorless and has a slightly salty, alkaline taste.

Baking powder was developed in the 19th century as a more convenient alternative to yeast and beaten egg whites for chemical leavening, and it became a staple of Anglo-American baking by the early 20th century.

Baking powder is essential in quick breads, cakes, cookies, biscuits, pancakes, and muffins, where it provides lift and a tender crumb structure without requiring fermentation time. It is used across numerous cuisines wherever flour-based quick breads are prepared. The typical ratio is 1 to 1.5 teaspoons of baking powder per cup of flour, though this varies with the acidity of other ingredients and desired crumb structure. Baking powder should be added to dry ingredients and mixed thoroughly before incorporating wet ingredients to ensure even distribution and consistent rise. Storage in a cool, dry place is critical, as moisture exposure reduces its efficacy.