How about a simple cabled hat for your little one? Because of the stretch in the ribbing and cables this hat fits most children up to age 8.
This is a great pattern to learn cables, it’s well written and easy to follow. You don’t need to purchase a lot of yarn either, just use up your worsted yarn stash!
Look at some of the great versions of this hat that ravelry users have created! The two versions using Misti Alpaca Worsted look so cozy. You could use any light to regular worsted weight yarn for this hat.