Are you out of baking powder and don’t want to leave the house, but want/need to make those cookies? You can easily make your own by combining the following ingredients and amounts: 1 teaspoon baking soda + 2 teaspoons cream of tartar + 1 teaspoon corn starch. You can increase or decrease the amount, and once mixed, store in the refrigerator. Best part – you can ensure that your homemade baking powder is aluminum free.