5 is not too young to help with cooking, you just have to work around it. Any cutting can be pre-done. Raw meat, eggs etc can be done by an adult or kept separately and just added (like a cooking show). Obviously hot things need to be carefully introduced. You will need extra time and patience to make it work.

We usually do pancakes or waffles one of the weekend mornings. It's a great way to kill some time when they wake up too early, the recipe is very simple, the kids leave you alone as soon as theirs are ready, and my wife can not only sleep a bit extra, but has nice breakfast ready to go when she does get up. It's also cheap if they mess it up.

Mixing, measuring, timing things. There's a lot of potential here for motor skills, numbers, and even reading because your child knows the names of the ingredients already and you can match them to words in the recipe. It's also a good life skill and they can help clean up too.

I love cooking and really want to share that with my kids. Since we eat early during the week I don't get to cook much, let alone cook with them, so we often do this kind of thing on weekends, including grocery shopping for the ingredients then making something with them. Even when they were too young to actually help cook, they enjoyed pulling up a chair to the counter, I'd give em a spoon, bowl and some 'ingredients' and they'd copy me.