My boys love to cook (something I am sure they will outgrow), they always want to get in the kitchen and get involved... things get messy but I don't want to discourage them, I married a man who had no clue how to cook, couldn't do laundry and had a streak of breaking vacuums. I may have boys but I am going to teach them how to cook, do laundry and clean. It's probably a futile effort but I feel better knowing I tried.
Things to expect when you let toddlers help in the kitchen... Flour everywhere. Fingerprints on every stainless steel appliance. Egg shells in the batter. Egg on the counter... Egg on the floor. Raw egg getting licked off the counter. A little bit extra cinnamon, on the dog. Where is Jacob? Hiding under the table with a raw cookie. The entire container of sprinkles on one cookie.... but trust me, it is fun cooking with toddlers you just have to be prepared.
Start by making sure you picked out a recipe that is safe, avoid raw meats, sharp stuff and hot stuff, use common sense (if you don't have any available common sense I recommend going back to the playroom and building a mega-block tower). Make sure you have one adult per little set of hands.
Now the fun part. Prep. Give the kids something to occupy them, and go pull out all your ingredients and measure them into separate little containers, have all your tools ready and clear all the dangerous stuff off the counter top. Get your kids (and yourself) in clothes that can get dirty. Put a stack of hand towels in the kitchen (you will need them and won't want to leave the room to get them.
Now go get the kids. If you have an apron & chef hat get that too. Now start mixing things up. Count scoops and pronounce the ingredients (mostly because it's fun listening to a toddler trying to say cinnamon or parmesan) Be prepared for some messes, and some taste testing. Give names to the flavors and textures, sugar is sweet and rough, like sand. Butter is creamy, flour is fluffy, pumpkin is gooey. Let them explore without being too concerned about the end result, we are learning here, not worrying about being Chopped.
Looks like fun? It is. Just be prepared for the outtakes.
Need a recipe that is fun and has edible raw batter, try snowball cookies, the kids can mix the dough with their hands and roll it too.