* not my cake in the pic just in example of how the buttercream looks. No matter how many times I scraped the sides little spaces appeared.
Sometimes it helps to gently stir the buttercream with a rubber scraper, stroking and smoothing to help remove bubbles. BettyA taught me a cool trick, years ago, for smoothing the top of a sheet cake - use the edge of a ruler which is wider than the cake. Be sure it is new and used for nothing but cakes. It works just like a scraper, but large enough to smooth the whole top in one pass. As to the corners, practice and more practice. In the meantime, you might want to put a decorative piping on each corner, like a row of shells climbing up each corner.
I used the ruler on the top of this cake:
I see this ? Is several months old — are you still working there —- having trouble? Have things improved for you? Maybe this will help: When I worked in a very busy bakery they mixed icing several ways/times throughout the day. 1st in Big (maybe 100 gallon?) bowls then it was transferred to 20 gallon bowl which would be mixed slowly before being transferred to “home sized” Kitchen Aid mixers at each decorator’s station. We would then slowly mix it for a minute before filling the piping bag. This went on several times a day. Get the picture? Long. Slow stirring breaks those bubbles making the icing soft & smooth as silk.
Does Walmart use real buttercream, or Bettercream whipped frosting? How is it stored? Where I work, we use Bettercream. We keep ours in the walk-in refrigerator, and I prefer it that way, so it's a bit cold, but not too much so. However, I know other decorators find it easier to work with straight from the freezer. If you're using Bettercream and have a walk-in freezer with a bit of space, perhaps experiment with it at different temperatures to see what works best for you. I also personally don't like using the quick icer. I find it easier and more efficient to just use a spatula to spread frosting on the cake and then smooth it with a scraper. If you're having trouble with the corners showing through, that way you can be a little more targeted with your frosting and spread a little extra on the edges before smoothing. But, that's just my personal preference. I'd recommend trying it without the quick icer at least once, just to see if it works better for you.
I also second Sandra's suggestion for decorative piping, or even sprinkles or something. Most of the cakes where I work are supposed to have either chocolate shavings or sprinkles along the bottom edge. It's great for hiding flaws when the frosting doesn't want to cooperate, and the sprinkles especially are also very popular with kids. I've had customers take cakes without sprinkles out of the display because they wanted that flavor and insist I take it to the back to add sprinkles to appease their kid. I'm also a fan of a border and flowers. On cakes where I just couldn't get the corners the way I wanted, I've piped a nice border and sometimes put a flower in each corner to cover it up and it's worked well.
corners: put all the icing on just the same way you always do -- then the icer tip is too flat for this next step -- get like a plain open coupler, no tip on it and pipe a fat round stripe of icing up each corner -- it will be sticking out -- looking odd -- now when you go to smooth you will have enough icing there to scrape away a pretty corner hidden underneath -- scrape once in each direction --
and yes give the icing a mix before you use it -- either by hand or in the mixer like lynne & all are saying ~ you could also add a bit of water to it --
there's different kinds of bubbles -- so if you mean the kind that appear on the surface of the icing -- if you run the smoother the other direction they will disappear --
I rarely do a square cake, but I am happy to hear the tip about piping the thick bead of frosting on each corner before smoothing, -K8memphis. I will try very heard to remember that!