Here’s an easy recipe for baking powder that does not contain aluminum, cornstarch or potato starch, in case you are allergic to any of these.
Homemade Baking Powder
1/4 cup tapioca flour or arrowroot flour
1/4 cup cream of tartar
2 Tablespoons baking soda
Mix well and place in labeled jar with tight-fitting lid. Use as regular baking powder.