While some recipes suggest substitutes like lemon juice or vinegar, I recommend sticking with cream of tartar for authentic snickerdoodles. These substitutes might alter the flavor and texture slightly, leaving you with cookies that don’t quite capture that classic snickerdoodle taste. So, next time you bake these browned butter snickerdoodles, remember that cream of tartar isn't just another ingredient—it's the secret to achieving that tangy, chewy perfection!