Baking Powder (Best Option)
3 teaspoons per 1 teaspoon of baking sodaBaking powder contains both an acid and a base, allowing it to release carbon dioxide gas when moistened and heated, which helps the frittata rise and become fluffy. Since frittatas rely on eggs for structure, the leavening effect is subtle but important for lightness.
When substituting, use about three times the amount of baking powder to replace baking soda because baking powder is less concentrated. Be cautious not to overuse it, as too much can cause a bitter taste.
The final frittata will be slightly lighter and airier compared to using baking soda, with no significant change in flavor, making it the best direct substitute.