Opening scene: "Can I lick the bowl now?" "No, not yet." "Ok, then, can I lick the spoon?" "No, not yet." Fade out from an impatient child freaking out, a mom looking like she made the wrong choice when deciding to bake with her kids, which leads to the abrupt ending of what was a hopeful, happy baking experience with your children. Sound familiar? Yea, I thought so...
As a professional chef, I have struggled for years with the concept of baking with young kids. It was a tough road to where I currently live, on, "Ok, you can help me in the kitchen" Street. It took some learning but, my secret is simple: weigh or measure out all of the ingredients beforehand. That's it! They may not enjoy missing that step, but who cares? Your sanity is at stake here, and I'm sure they would make a deal with the devil for the baked goods anyway.
If you have everything prepared and ready for mixing, less drama ensues. I find, that there is also less of a mess, less fighting over who gets to do what, the fucking confection goes in the oven way faster, and at the end, you are less likely to give your children up for adoption and move back to the city where you were once single and happy. Now, that's what I call a win-win!
Once children become older and more "civilized" give them tasks for more developed kids. Until then, give my way a try. You might be surprised.