All of my recipes contain unsalted butter UNLESS OTHERWISE SPECIFIED. 99% of the time my recipes are made using Challenge Butter. Whatever you use, please use REAL BUTTER unless otherwise instructed. Margarine, butter spreads made with oil, shortening, and oil are NOT REAL BUTTER and will perform differenly. Also: using the cheapest butter at the store may cause your recipes to have issues. I know butter is expensive but you get what you pay for. Learn all about unsalted butter vs salted butter. Learn how to soften butter quickly.