The tone in the kitchen

A gentle answer turns away wrath, but a harsh word stirs up anger.Proverbs 15:1

You already know this one. You know it at 5:40 in the afternoon when the pan is burning and somebody is screaming about a sock.

Knowing it is not the problem. The problem is that gentleness is a thing you spend, and by evening you are spent.

So this is not a rebuke. If you were harsh today, say so to the small person, plainly, and let them watch you do it. A child who sees an adult apologize learns something they cannot be told.