Patsy, I hear ya'. I googled which to use and found recipes that used one or the other. I even saw a recipe that used both! I did come upon a recipe that reported to be an authentic, old fashioned recipe that used something called 'baker's ammonia' (ammonium bicarbonate) that pre-dated baking soda and has a different chemical make-up. This can be purchased on Amazon for about $10/lb. If you want to check out her recipe it's called Traditional Speculoos Cookies on The Daring Gourmet website. Good luck.
Patsy, I hear ya'. I googled which to use and found recipes that used one or the other. I even saw a recipe that used both! I did come upon a recipe that reported to be an authentic, old fashioned recipe that used something called 'baker's ammonia' (ammonium bicarbonate) that pre-dated baking soda and has a different chemical make-up. This can be purchased on Amazon for about $10/lb. If you want to check out her recipe it's called Traditional Speculoos Cookies on The Daring Gourmet website. Good luck.