Add cornstarch to make it less runny

Occasionally, adding too much vanilla extract or other liquids to buttercream can result in watery frosting. Adding extra powdered sugar might not be the best course of action if you have already added the ideal amount because it could make the frosting too sweet. In this situation, a small amount of cornstarch added to the buttercream can work miracles. The icing can be made more substantial by adding cornstarch, and the greatest part is that the flavor won't be significantly changed. This straightforward advice is crucial if you're sick of sloppy frosting, and it's quite simple to apply.

Use one teaspoon of cornstarch for each cup of confectioners' sugar. Avoid blending the cornstarch directly into the frosting for optimal results (this can cause lumping). Instead, create a slurry using just enough milk or cream to help the cornstarch dissolve effectively. Although it may seem counterproductive to add additional liquid to the icing, the cornstarch will function as intended. Therefore, save your frosting the next time it becomes runny since it can still be fixed.