Scrape the sides of the bowl during the mixing process

When using a mixer to make traditional buttercream frosting, the straightforward procedure of scraping down the bowl is crucial. Although the mixer does a good job of catching many ingredients on its own, it doesn't always do so perfectly. The best course of action is to pause the mixer occasionally, grab a rubber spatula, and scrape the bowl's sides. If necessary, you can also lower the bowl so that you can completely reach under the attachment to scrape the bottom. You'll probably discover excess butter or sugar clumps adhering to the sides and bottom after doing this.

Bypassing this step can result in parts of the final frosting that wasn't completely incorporated. This can result in the inconsistent flavoring of the buttercream. Additionally, attempting to incorporate the excess butter into the frosting at the last minute may result in unintended lumps because the extra butter on the sides is probably tougher than the light frosting.