Baking Powder (Best Option)
3 teaspoons per 1 teaspoon of baking sodaBaking powder contains both an acid and a base, allowing it to react and produce carbon dioxide gas without additional acidic ingredients. This makes it a reliable leavening agent substitute in recipes like tiramisu that require gentle aeration.
When substituting, use about three times the amount of baking powder as baking soda to achieve similar leavening. Be cautious not to overuse, as excessive baking powder can impart a bitter taste.
The final tiramisu will have a similar airy texture, though the slight difference in acidity may subtly affect flavor balance, which is generally negligible in the overall dessert.