I messed up on some Italian buttercream recently and wanted some experienced opinions on fixing it. I'm mainly wondering if it's worth it to mess up my mixer and have to clean up. I inadvertently read the butter wrong on the recipe and only used about half as much. It had the consistency of smooth gravy. I kept it and made a new batch. Can I just add more whipped butter at room temp using a paddle or whip attachment to fix it? This is what I get for procrastinating during the day and working late at night. But the cake ended up fine.