How Does baking powder makes pastries hard?

Baking powder contains a combination of an acid and a base that react to produce carbon dioxide gas when moistened and heated. This gas creates bubbles, which help the pastry rise and achieve a light texture. However, using too much baking powder can lead to an overly dense or hard texture, as the excess gas can cause the structure to collapse or become tough. Additionally, insufficient mixing or inadequate liquid can inhibit the proper expansion of the pastry, resulting in a harder final product.